This invention relates to new pyrazolo [4, 3-d] pyrimidine derivatives and to their use in suitable utilities, especially in cancer therapy and agricultural practice.

The cell division cycle is an evolutionarily conserved process in all eukaryotic cells to control growth and division. The cell cycle consists of four distinct stages illustrated in Figure 7, the Gl, S, G2 and M phase. Normal cellular proliferation is initiated and tightly controlled by a series of regulatory mechanisms that either permit or prevent cell cycle progression. In every phase, there are protein complexes, the cyclins and cyclin-dependent kinases regulating and advancing the cell cycle. Figure 7 shows the cell division cycle (cdc) consisting of four phases G1, S, G2 and M. Mitosis (the actual division) occurs in M-phase. In every phase, there are specific cyclin-dependent kinase complexes present (CDK's).

Proliferative disorders such as cancer are recognised as diseases of the cell cycle. It has been found that in tumour cells, the mechanisms that normally function to restrain cell division are defective, whilst those that promote division become more active. The genes responsible for these changes in growth and proliferation are generally named"tumour suppressors"and"oncogenes". Cell-cycle regulatory compounds are pivotal in the modulation of abnormal cellular proliferation as they provide ideal targets for therapy for a range of proliferative disorders.

A series of 3-, 7-disubstituted pyrazolo [4, 3-d] pyrimidines are useful for inhibition of cyclin-dependent kinases (preferably p34°dc2/cyclin B). Hence they can be used as antimitotic and apoptotic drugs, particularly as anticancer drugs and herbicides.

Likewise, the compounds can be used as anti-fungal agents, which may have high value in the treatment of aspergillosis, penicilliosis, actinomycosis and the like.

Difference in homology of insect CDK genes permit selection of compounds of this invention which discriminate between insect/mammalian CDK enzymes and thus leads to insecticides.

Summary of the Invention It is an object of this invention to provide antimitotic, anticancer, herbicidal, fungicidal and insecticidal compounds having improved selectivity and efficiency index, i. e. that are less toxic yet more efficacious than analogues known heretofore.

It is an object of this invention to provide 3,7-disubstituted pyrazolo [4,3- d] pyrimidines, which inhibit the cdks, cell proliferaton or block cytokinin receptors.

A further object of this invention is to provide a pharmaceutical composition, which comprises a 3, 7-disubstituted pyrazolo [4,3-d] pyrimidine, and a pharmaceutically acceptable carrier.

A further object of this invention to provide a method for inhibiting cell proliferation and/or inducing apoptosis to a mammal or plant in need of an effective amount of 3,7-disubstituted pyrazolo [4,3-d] pyrimidines.

This invention further constitutes a method for inhibiting cell proliferation to a plant in need of an effective amount 3,7-disubstituted pyrazolo [4,3-d] pyrimidines.

The solution of this object are 3-, 7-disubstituted pyrazolo [4,3-d] pyrimidines represented by the general formula I and pharmaceutically acceptable salts thereof, wherein R3 is selected from the group consisting of alkyl, cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl alkyl, cycloheteroalkyl, aryl, heterocycle, heteroaryl, arylalkyl, heteroarylalkyl, and heteroalkyl, wherein each of the groups may optionally be substituted, R7 is selected from the group consisting of halogen, hydroxyl, hydroxylamino, amino, carboxyl, cyano, nitro, amido, sulfo, sulfamido, carbamino, unsubstituted or

substituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted heteroarylakyl, substituted or unsubstituted cycloalkyl alkyl, substituted or unsubstituted cycloheteroalkyl alkyl ; R7'-X-wherein X is an-NH-,-N (alkyl)-,-O-or-S-moiety and R7'is selected from the group consisting of H, alkyl, cycloalkyl, aryl, alkylcycloalkyl, arylalkyl, heterocycle, heterocycloalkyl, substituted alkyl, substituted cycloalkyl, substituted aryl, substituted arylalkyl, substituted heterocycle, substituted heteroaryl, substituted heteroarylalkyl, substituted heteroalkyl, substituted cycloalkyl alkyl and substituted cycloheteroalkyl alkyl.

If the above groups are substituted, they are preferably substituted by halogen, hydroxyl, amino, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, carbamino, alkyl, alkoxy, and/or substituted alkyl group, in particular by more than one of the above substituents, preferably by 1 to 3 substituents.

In another embodiment, this invention is a method for inhibiting cdks and cell proliferation and/or for inducing apoptosis in plants, comprising administering an effective amount of a composition comprising one or more compounds according to claim 1 to the plant. The cdk inhibiting molecules are useful for treating disorders, some of them involving cell proliferation, and thus are useful as herbicides.

In yet another embodiment, this invention is a pharmaceutical composition comprising one or more compounds according to claim 1 in an admixture with one or more pharmaceutical excipients.

In still another embodiment, this invention is a composition comprising one or more compounds according to claim 1 useful for treating fungal infections (fungi) in plants.

In another embodiment, this invention is a composition comprising one or more compounds according to claim 1 useful for treating insects and yeasts on plants.

3,7-disubstituted pyrazolo [4,3-d] pyrimidines result in the acquisition of extremely high potency against plant viruses on the part of the defined compounds.

As used herein, and unless modified by the immediate context :

"Halogen"preferably refers to fluorine, bromine, chlorine and iodine atoms.

"Hydroxy"refers to the group-OH.

"Mercapto"refers to group-SH.

"Alkyl"preferably refers to branched or unbranched Cl-Cs alkyl chain which is saturated or unsaturated. Thus, the term"alkyl"when used herein encompasses alkyl alkenyl and alkinyl groups. Alkenyl groups preferably have 2 to 8 carbon atoms, alkinyl groups preferably have 3 to 8 carbon atoms. Such groups as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, allyl, ethinyl, propargyl, and the like can exemplify this term.

"Substituted alkyl"preferably refers to alkyl as described above including one to six, in particular 1 to 3 substituents such as hydroxyl, mercapto, alkylthio, halogen, alkoxy, acyloxy, amino, acylamino, hydrazino, carbamoyl, amido, carboxyl, sulfo, acyl, guanidino and the like. These groups may be attached to any carbon atom of the alkyl moiety.

"Alkoxy"denotes the group-OR, where R is preferably alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl or substituted cycloheteroalkyl as defined herein.

"Alkylthio"denotes the group-SR, where R is preferably as defined for"alkoxy" group.

"Sulfo"denotes the group-SO3R, where R is preferably H, alkyl or substituted alkyl as defined above.

"Sulfamido"denotes to the group S02NRR"where R and R"is preferably H, alkyl or substituted alkyl as defined above.

"Acyl"denotes groups-C (O) R, where R preferably is alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substtituted arylalkyl, cycloalkyl, substituted cycloalkyl as defined herein.

"Aryloxy"denotes groups-OAr, where Ar is preferably an aryl, substituted aryl, heteroaryl or substituted heteroaryl group as defined herein.

"Alkylamino"denotes the group-NRR', where R and R'may independently be hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl or substituted heteroaryl as defined herein.

"Amido"denotes the group-C (O) NRR', where R and R'may independently be hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl as defined herein.

"Carboxyl"denotes the group-C (O) OR, where R is preferably hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, hetaryl or substituted hetaryl as defined herein.

"Acylamino denotes the group-NHCOR, where R may be alkyl, substituted alkyl, heterocycle, aryl, substituted aryl, heteroaryl and substituted heteroaryl as defined herein.

Carbamoylamino denotes the group NHCOOR, where R is preferably alkyl or aryl.

"Aryl"or"Ar"refers to an aromatic carbocyclic group having at least one aromatic ring (e. g. , phenyl or biphenyl) or multiple condensed rings in which at least one ring is aromatic (e. g. , 1,2, 3,4-tetrahydronaphthyl, naphthyl, anthryl, or phenanthryl).

Preferably, the aryl group has more than six, in particular 6 to 10 carbon atoms.

"Substituted aryl"refers to aryl as described above which is optionally substituted with one or more functional groups, in particular 1 to 3 substituents, such as halogen, alkyl, hydroxy, amino, acylamino, carbamoylamino, hydrazino, mercapto, alkoxy, alyklthio, alkylamino, amido, carboxyl, nitro, sulfo and the like as defined herein.

"Heterocycle"refers to a unsaturated or aromatic carbocyclic group preferably having 1 to 3 rings and having at least one, preferably 1 to 3 and in particular 1 or 2 hetero atoms, such as N, O or S, within the ring; the ring can be single (e. g. pyranyl, pyridyl or furyl) or multiple condensed (e. g. , quinazolinyl, purinyl, quinolinyl or benzofuranyl) which can optionally be unsubstituted or substituted with, e. g., halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy, alkylamino, acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio carboxyl, amido, sulfo, sulfamido, and the like as defined above. The heterocycle groups preferably has 5 to 10 ring atoms, which are either cabon atoms or hetero atoms as defined above.

"Heteroaryl"refers to a heterocycle in which at least one heterocyclic ring is aromatic.

"Substituted heteroaryl"refers to a heterocycle optionally mono or poly substituted with one or more functional groups, preferably 1 to 6, in particular 1 to 3 substituents, e. g. , halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy,

alkylamino, acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio carboxyl, amido, sulfo, sulfamido, and the like.

"Arylalkyl"refers to the group-R-Ar where Ar is an aryl group and R is alkyl or substituted alkyl group as defined above. The aryl groups can optionally be unsubstituted or substituted as defined above with, e. g. , halogen, amino, acylamino, carbamoylamino, hydrazino, acyloxy, alkyl, hydroxyl, alkoxy, alkylthio, alkylamino, amido, carboxyl, hydroxy, aryl, nitro, mercapto, sulfo and the like.

"Heteroalkyl"refers to the group-R-Het where Het is a heterocycle group and R is a alkyl group as defined above. Heteroalkyl groups can optionally be unsubstituted or substituted as defined above with e. g. , halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy, alkylamino, acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio, carboxyl, amido, sulfo, sulfamido, and the like.

"Heteroarylalkyl"refers to the group-R-HetAr where HetAr is an heteroaryl group and R is alkyl or substituted alkyl as defined above. Heteroarylalkyl groups can optionally be unsubstituted or substituted as defined above with, e. g. , halogen, alkyl, substituted alkyl, alkoxy, alkylthio, nitro, mercapto, sulfo and the like.

"Cycloalkyl"refers to a divalent cyclic or polycyclic alkyl group containing preferably 3 to 15 carbon atoms.

"Substituted cycloalkyl"refers to a cycloalkyl group comprising one or more substituents as defined above with, e. g. , halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy, alkylamino, acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio, carboxyl, amido, sulfo, sulfamido, and the like.

"Cycloheteroalkyl"refers to a cycloalkyl group as defined above wherein one or more, preferably 1 to 3, of the ring methylene group is replaced with a heteroatom (e. g. , NH, O, S) "Substituted cycloheteroalkyl"refers to a cycloheteroalkyl group as herein defined which contains one or more substituents as defined above, such as halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy, alkylamino, acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio, carboxyl, amido, sulfo, sulfamido and the like.

"Cycloalkyl alkyl"denotes the group-R-cycloalkyl where cycloalkyl is a cycloalkyl group as defined above and R is an alkyl or substituted alkyl as defined above.

Cycloalkyl groups can optionally be unsubstituted or substituted as defined above with e. g. , halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy, alkylamino,

acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio, carboxyl, amido, sulfo, sulfamido and the like.

"Cycloheteroalkyl alkyl"denotes he group-R-cycloheteroalkyl where R is a alkyl or substituted alkyl as defined above and cycloheteroalkyl as as defined above. Cycloheteroalkyl groups can optionally be unsubstituted or substituted as defined above with e. g. halogen, amino, hydroxy, cyano, nitro, mercapto, alkoxy, alkylamino, acylamino, carbamoylamino, acyloxy, dialkylamino, alkylthio, carboxyl, amido, sulfo, sulfamido, and the like.

In a preferred embodiment the invention relates to 3-, 7-disubstituted pyrazolo [4,3-d] pyrimidines, which inhibit the cyclin-dependent and MAP kinases have formula I and the pharmaceutically acceptable acid salts thereof, wherein R3 is selected from an alkyl, cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, cycloheteroalkylalkyl, cycloalkyl alkyl, aryl, arylakyl, heteroaryl, heteroarylalkyl, wherein each of the groups may be optionally be subsituted by a halogen; R7 is selected from the group consisting of halogen, hydroxyl, hydroxylamino, amino, hydrazino, carboxyl, cyano, nitro, amido, sulfo, sulfamido, carbamino, NHCONH2, NHC (=NH) NH2, alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heteroalkyl, heteroaryl, heteroarylalkyl, cycloheteroalky, cycloheteroalkylalkyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto,

carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; . R7'-X, wherein X is-NH-,-0-,-S- ; R7'-X, wherein X is preferably-N (alkyl)- selected at each occurrence from the group methyl, ethyl, propyl, isopropyl, ethinyl, allyl, propargyl, and isopent-2-en- 1-yl ; R7'is Cl-C8 branched or unbranched alkyl, alkenyl or alkinyl preferentially selected from the group methyl, ethyl, isopropyl, butyl, isobutyl, allyl, propargyl, isopent- 2-en-1-yl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; . acyl,-C (O) R, wherein Ra is Cl-C6 branched or unbranched alkyl, alkenyl or alkinyl preferentially selected from the group methyl, ethyl, isopropyl, butyl, isobutyl, allyl, propargyl, isopent-2-en-1-yl, and 2-methylallyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; . amido, -C (O) NRbRc, wherein Rb and Re is independently H, Cl-C6 branched or unbranched alkyl, alkenyl or alkinyl preferentially selected from the group methyl, ethyl, isopropyl, butyl, isobutyl, allyl, propargyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; sulfo,-S03Rd, wherein Rd is H, Cl-C6 branched or unbranched alkyl, alkenyl or alkinyl preferentially selected from the group methyl, ethyl, isopropyl, butyl, isobutyl, allyl, propargyl, isopent-2-en-1-yl, and 2-methylallyl which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl,

cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alyklthio and carbamoyl group; cykloalkyl is C3-C15 cycloalkyl is preferentially selected from the group cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or adamantyl; substituted cycloalkyl is C3-C15 cycloalkyl is preferentially selected from the group cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or adamantyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; cycloalkyl alkyl is Rffcycloalkyl), wherein Rf is C,-C6 alkyl, alkenyl or alkinyl preferentially selected from the group methyl, ethyl, isopropyl, butyl, allyl, propargyl, isopent-2-en-1-yl and 2-methylallyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group, . cykloalkyl is C3-Cls cycloalkyl is preferentially selected from the group cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or adamantyl; substituted cycloalkyl is C3-C15 cycloalkyl is preferentially selected from the group cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or adamantyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; . aryl is preferentially selected from the group phenyl, biphenyl, naphthyl, tetrahydronaphtyl, fluorenyl, indenyl or fenanthrenyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group,

heterocycle is preferentially selected from the group thienyl, furyl, pyranyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, isothiazolyl, isoxazyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group ; . heteroalkyl is-Rg-Het, wherein w Rg is Ci-C6 alkyl, alkenyl or alkinyl preferentially selected from the group methylen, 1,2-ethyliden, 1, 3-propiliden, 1, 4-butyliden, pentamethylen, hexamethylen, ethylendiyl, allyl-1, 3-diyl, methylethan-1, 1-diyl, methylethan- 1,2-diyl, butan-1, 3-diyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, cyano and Het is preferentially selected from the group thienyl, furyl, pyranyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, isothiazolyl, isoxazyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; heteroaryl is-Rh-HetAr, wherein . Rh is Ci-C6 alkyl, alkenyl or alkinyl preferentially selected from the group methylen, 1,2-ethyliden, 1,3-propiliden, 1,4-butyliden, pentamethylen, hexamethylen, ethylendiyl, allyl-1, 3-diyl, methylethan-1, 1-diyl, methylethan- 1,2-diyl, butan-1, 3-diyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, cyano; HetAr is preferentially selected from the group benzothienyl, naphthothienyl, benzofuranyl, chromenyl, indolyl, isoindolyl, indazolyl, qinolyl, isoqinolyl, ftalazinyl, qinaxalinyl, cinnolinyl, qinazolinyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido,

sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; arylalkyl is-RjAr, wherein Ri is Ci-C6 alkyl, alkenyl or alkinyl preferentially selected from the group group methylen, 1,2-ethyliden, 1,3-propiliden, 1,4-butyliden, pentamethylen, hexamethylen, ethylendiyl, allyl-1, 3-diyl methylethan-1,1- diyl, methylethan-1, 2-diyl, butan-1, 3-diyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, cyano; Ar is preferentially selected from the group phenyl, biphenyl, naphthyl, tetrahydronaphtyl, fluorenyl, indenyl or fenanthrenyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; cycloheteroalkyl is preferentially selected from the group piperidinyl, piperazinyl, morfolinyl, pyrrolidinyl, imidazolidinyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; . cycloheteroalkyl alkyl,-Rj (cycloheteroalkyl), wherein * Rj is arylalkyl-RiAr, wherein . Ri is C-C6 alkyl, alkenyl or alkinyl preferentially selected from the group group methylen, 1,2-ethyliden, 1,3-propiliden, 1,4-butyliden, pentamethylen, hexamethylen, ethylendiyl, allyl-1, 3-diyl, methylethan-1,1- diyl, methylethan-1, 2-diyl, butan-1, 3-diyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, cyano, and Ar is preferentially selected from the group phenyl, biphenyl, naphthyl, tetrahydronaphtyl, fluorenyl, indenyl or fenanthrenyl substituted independently at each occurrence with 0-5 substituents selected from the

group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group, and cycloheteroalkyl is preferentially selected from the group piperidinyl, piperazinyl, morfolinyl, pyrrolidinyl, imidazolidinyl substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group; heteroarylalkyl is-Rk-HetAr, wherein Rk is Cl-C6 alkyl, alkenyl or alkinyl preferentially selected from the group group methylen, 1,2-ethyliden, 1,3-propiliden, 1,4-butyliden, pentamethylen, hexamethylen, ethylendiyl, allyl-1, 3-diyl methylethan-1,1- diyl, methylethan-1, 2-diyl, butan-1, 3-diyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, cyano, and HetAr is preferentially selected from the group benzothienyl, benzofuranyl, chromenyl, indolyl, isoindolyl, indazolyl, qinolinyl, phthalazinyl, qinoxalinyl, qinazolinyl, karbazolyl, akridinyl, indolinyl, and isoindolinyl, which is substituted independently at each occurrence with 0-5 substituents selected from the group halogen, hydroxy, alkoxy, amino, hydrazo, mercapto, carboxyl, cyano, nitro, amido, sulfo, sulfamido, acylamino, acyloxy, alkylamino, dialkylamino, alkylthio and carbamoyl group.

The following derivatives are particularly preferred, namely: 7- (2-hydroxy-3- chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, cyclopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-4-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, cyclopropyl, 3-pentyl benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-5-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, cyclopropyl, 3- pentyl.. benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-6-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy- 3-iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-

d] pyrimidine, 7-(2-hydroxy-4-iodobenzyl) amino-3-(methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-5-iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- <BR> <BR> <BR> <BR> hydroxy-6-iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-3-bromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 3-pentyl, 7- (2- <BR> <BR> <BR> <BR> hydroxy-4-bromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-hydroxy-5-bromobenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-6- bromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2-hydroxy-3-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-hydroxy-4-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- hydroxy-5-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 6- (2-hydroxy-6-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-dihydroxy-4- methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 5-dihydroxy-4-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 6-dihydroxy-3- methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 3-dihydroxy-3-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 5-dihydroxy-3- methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7-(2, 6-dihydroxy-4-methoxybenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3-dihydroxy-4- chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 3-dihydroxy-4-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 5-dihydroxy-4- chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7-(2, 6-dihydroxy-4-chlorobenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dihydroxy-4-

bromoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3- d] pyrimidine, 7- (2, 6-dihydroxy-4-iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2, 6-dihydroxy-3-chlorobenzyl) amino- 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6- dihydroxy-3-bromobenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2,6-dihydroxy-3-iodobenzyl)amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dihydroxy-3- fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 6-dihydroxy-3, 5-dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dihydroxy-3,5- dibromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 6-dihydroxy-3, 5-diiodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dihydroxy-3,5- difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- bromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7- (3-bromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-bromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-iodobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- chlorobenzylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine 7- (4-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-acetylbenzyl)amino-3-(methyl, ethyl,

isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-acetylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4- acetylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-karboxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-karboxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-acetoxybenzyl) amino- 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- acetoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d]pyrimidine, 7-(4-acetoxybenzyl)amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl)pyrazolo [4,3-d]pyrimidine, 7-(2-nitrobenzyl)amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4- nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7- (2-cyanobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-cyanobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-cyanobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (5-nitro-2- methylbenzyl) amino-3- (methyl, ethyl, isopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- methylaminobenzyl)amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(3-methoxybenzyl) amino- 3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4- methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7- (2-hydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-hydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-hydroxybenzyl) amino- 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-

hexylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-hexyloxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-ethoxybenzyl) amino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-ethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- ethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-ethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-penthylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- penthyloxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-fenoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-fenylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-propylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4- propyloxybenzyl) aminopurin, 7- (4-oktylbenzylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-octyloxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- ethyloxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3- d] pyrimidine, 7- (3, 4-diacetoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5-diacetoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 67- (2, 5- diaminobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- djpyrimidine, 7- (3, 5-dibromobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3, 5-dibromo-4-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3- dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7-(2, 4-dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 5-dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6- dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3, 4-dichlorobenzyl) amino 3- (methyl, ethyl, isopropyl, 3-pentyl,

benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5-dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,4, 5- tetrafluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2-chloro-3, 6-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (5-chloro-2-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,4- trifluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d) pyrimidine, 7- (2, 3,5-trifluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4, 5-trifluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4,5- trifluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 3, 6-trifluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-chloro-2, 6-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-6- fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 6-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4- difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 5-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [5-fluoro-2- (trifluoromethyl) benzyl] amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [4-fluoro-2- (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2-chloro- 5- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-(difluoromethoxy)benzyl)amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- (difluoromethoxy) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(4-(difluoromethoxy)benzyl)amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2-fluoro-5-

(trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [3-fluoro-4- (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2-fluoro-4- (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- (trifluoromethylthio) benzylamino) purin, 7- [2-fluoro-3- (trifluoromethyl) benzy] lamino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-chloro-6-fluoro-3-methylbenzylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(6-chloro- 2-fluoro-3-methylbenzylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- [3-chloro-2-fluoro-5- (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [3-chloro-2-fluoro-6- (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-difluoro-4-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6- difluoro-3-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-fluoro-6- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-chloro- 2,6-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [3- (trifluoromethylthio) benzy] lamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-fluoro-4- methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- [4-fluoro-3-methylbenzyl] amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (5-fluoro-2-methylbenzylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-chloro-3,6-difluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [4- (trifluoromethylthio) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-fluoro-5- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-chloro-4-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-

(trifluoromethoxy) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2- (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [4-chloro-3- (trifluoromethyl) benzyl] amino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-fluoro-3- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [3, 5- di (trifluoromethyl) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [3- (trifluoromethoxy) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [4- (trifluoromethoxy) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- (trifluoromethyl) benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [4- (diethylamino) benzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4-dihydroxybenzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5- dihydroxybenzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3, 4-dihydroxybenzyl] amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-ethylenedioxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4- dihydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 5-dihydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, isopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dihydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4- dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3, 4-dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5-dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3- dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-

d] pyrimidine, 7- (2, 4-dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 5-dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6- dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-hydroxy-4-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-3-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- hydroxy-3-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-4-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- <BR> <BR> <BR> <BR> hydroxy-2-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-hydroxy-5-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- <BR> <BR> <BR> <BR> hydroxy-4-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-hydroxy-3-methoxybenzylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- <BR> <BR> <BR> <BR> hydroxy-6-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-hydroxy-S-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4, 5- dimethoxy-2-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4-dimethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3- dimethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 4-dimethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dimethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dimethyl-4- hydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3, 5-dimethyl-4-hydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-fluoro-4-hydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-fluoro-4- methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-

d] pyrimidine, 7- (3, 4-dinitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3, 5-dinitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-methyl-5- nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-methyl-4-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3, 4-diiodo-4-hydroxybenzyl) amino- 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- chloro-3, 4-dimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-chloro-3, 5-dinitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-4- fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-chloro-4-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-6-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-chloro-2- methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-chloro-4-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (5-chloro-2-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro- 4-fluorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-chloromethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-5-nitrobenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-6- nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-chloro-3-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (5-chloro-2-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-bromo-4- hydroxybenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3, 5-dibromo-4-hydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-bromo-4-methoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- butoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-

d] pyrimidine, 7- (4-butoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-/t-butyl/benzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-t-butyl-2, 6- dimethylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7-(2-aminobenzyl) amino-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-aminobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-aminobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-amino- 6-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-amino-4-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-amino-3-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-amino- 4-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2-amino-6-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2, 6-diamino-3-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6- <BR> <BR> <BR> <BR> diamino-4-chlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(4-amino-3-chlorobenzyl) amino-3-(methyl, ethyl, isopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-amino-5- dichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (5-amino-2-methylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-amino-3-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-amino- 3-nitrobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-benzyloxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-acetylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-acetylbenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,4- trimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 4, 5-trimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4, 6-trimethoxybenzyl) amino-3-

(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3, 4,5- trimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 4,6-trimethoxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3,4-trihydroxybenzy) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4,6- trihydroxybenzy) lamino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 3,4-trihydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4, 5-trihydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4,6- trihydroxybenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 4, 5-trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4,5-trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4,6- trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 3,4-trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,5-trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3,6- trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 5,6-trichlorobenzyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-anilino-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2, 4-bis (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2, 5- bis (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2, 4-bis (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5- bis (trifluoromethyl) anilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-bromoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-bromoanilino)-3- (methyl, ethyl, isopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-bromoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-bromo-2- chloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-

d] pyrimidine, 7- (4-bromo-3-chloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2-bromo-6-chloro-4- (trifluoromethyl) anilino] - 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4- bromo-5, 6-difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-bromo-4, 6-difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-bromo-2, 6- difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-bromo-2-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-bromo-4-fluoroanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-bromo-4- methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-bromo-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 6- (4-bromo-3-methylanilino))-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2-bromo-4- <BR> <BR> <BR> (trifluoromethoxy) anilino]-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [3-bromo-4- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- [4-bromo- 2- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-bromo-4, 5, 6-trifluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4- dibromoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 5-dibromoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4-dibromo-3, 6-dichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2, 6-dibromo-4- fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- [2, 6-dibromo-4- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- [2, 4-dibromo-6- (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- [2, 6-dibromo-4- (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-dichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4-

dichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7- (2, 5-dichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 6-dichlorooanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4-dichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5- dichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- [2, 6-dichloro-4- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-[2, 4-dichloro-6- (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7-[2, 6-dichloro-4-(trifluoromethyl) anilino]-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4- difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 5-difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2, 6-difluoroanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 4-difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 5- difluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7-(2-difluoromethoxyanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-difluoromethoxy-5-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-difluoro-6- nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 4-difluoro-6-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2, 4-dijodoanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-dimethylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4- dimethylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2, 3-dimethyl-6-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2,4-dimethoxyanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3-dimethoxyanilino) -3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3-

dinitro-6-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-hydroxy-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-chloroanilino)-3-(methy, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-chloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-chloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, (7-chloro-2, 6- dibromo-4-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- <BR> <BR> <BR> <BR> d] pyrimidine, 7- (2-chloro-4-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-5-fluoroanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2-chloro-6-fluoroanilino)- 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3- chloro-2-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-chloro-4-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-chloro-2-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (5-chloro-2-fluoroanilino)- 3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- <BR> <BR> <BR> <BR> chloro-4-fluoro-5-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(5-chloro-4-fluoro-2-nitroanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(5-chloro-2- hydroxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (4-chloro-2-iodoanilino)-3- (methyl, ethyl, isopropyl, 3- pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-chloro-4-iodoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2-chloro-6- methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (3-chloro-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-[3-chloro-4-(trifluoromethoxy)anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- [4-chloro-2- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d]pyrimidine, 7-(2-fluoroanilino)-3-(methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3- fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl,

benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-fluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-fluoro-4- iodoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (2-fluoro-5-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-fluoro-4-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-fluoro-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-cyklopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-fluoro-4-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-fluoro-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-fluoro-4-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (5-fluoro-2- <BR> <BR> <BR> <BR> methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4-fluoro-2-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-fluoro-3- <BR> <BR> <BR> <BR> nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-(2jodoanilino)-3-(methyl, ethyl, isopropyl, 3- pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-[2-fluoro-4- (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-iodo-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- methoxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-methoxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- methoxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-methoxy-5-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-methoxy- 6-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-methoxy-2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (5-methoxy- 2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl,

benzyl) pyrazolo [4,3-d] pyrimidine, 6- [4-methoxy-3- (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-methylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-[2-methyl-3-(trifluoromethoxy) anilino]-3-(methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d]pyrimidine, 7-[2-methyl-4- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-[2-(methylthio)anilino]-3-(methyl, ethyl, <BR> <BR> isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- [4- (methylthio) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-nitroanilino)-3-(methyl, ethyl, isopropyl, 3- pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2-nitro-4, 5, 6-trifluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-f2- nitro-4- (trifluoromethoxy) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, <BR> <BR> cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2-nitrotetrafluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,4, 5, 6-pentabromoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 6-(2, 3,4, 5, 6-pentafluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-(2, 3,4, 5- tetrachloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl)pyrazolo[4,3-d]pyrimidine, 7-(2, 3,5, 6-tetrachloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (4- (1, 1,2, 2- tetrafluoroethoxy) anilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3,4, 5,-tetrafluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,4, 6, - <BR> tetrafluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl,

benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3,5, 6,-tetrafluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-[2, 3,5, 6- tetrafluoro-4- (trifluoromethyl) anilino]-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4,6-tribromoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4, 6-tribromo-3, 5-dijodoanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3, 4-trichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4, 5-trichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 4, 6-trichloroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 4,5- trifluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3, 5-trifluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3,6- trifluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2, 3, 4-trifluoroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (2- trifluoromethoxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-trifluoromethoxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4- trifluoromethoxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 3, 4-trifluoro-6-nitroanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2,4, 5-trimethylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2, 4, 6-trimethylanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-chloro-4- carboxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-carboxy-4-hydroxyanilino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- cyclohexylamino-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-cyclopentylamino-3- (methyl, ethyl, isopropyl,

3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-cyclobutylamino-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-allylamino-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-dlpyrimidine, 7-diallylamino-3-(methyl, ethyl, isopropyl, 3- pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine 7-isopentylamino-3-(methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3, 3- <BR> <BR> <BR> dimethylallylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (3-hydroxymethyl-3-methylallyl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7-propargylamino-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7-furfurylamino-3- (methyl, ethyl, isopropyl, 3- pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (oxazol-4-yl) amino-3- (methyl, ethyl, isopropyl, 3-pentyl, cyclopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (2-pyridylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (3-pyridylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-pyridylamino)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (4-morfolinyl)- 3- (methyl, ethyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (1-chinuklidinyl)-3- (methyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (1-etyleniminyl)-3- (methyl, ethyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (1-propyleniminyl)-3- (methyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3- d] pyrimidine, 7- (1-pyrolidinyl)-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (1-piperidinyl)-3- (methyl, ethyl, isopropyl, 3- pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- (1-piperazinyl)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4,3-d] pyrimidine, 7- pyrazol-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3- d] pyrimidine, 7-imidazol-3- (methyl, ethyl, isopropyl, 3-pentyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (1-imidazolinyl)-3- (methyl, ethyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine, 7- (1-pyrazolinyl)-3- (methyl, ethyl, isopropyl, 3-pentyl, cyklopropyl, benzyl) pyrazolo [4, 3-d] pyrimidine.

The novel compounds of this invention per se or as intermediates in the preparation of novel compound having a wide variety of industrial utilities.

The compounds of the formula I and their pharmaceutically acceptable salts inhibit selectively the enzyme p34°ac2/cyclin B kinase and related cdks (cdkl, cdk2, cdk5, cdk7, MAP kinases).

In another embodiment, this invention is a method for inhibiting cdks and cell proliferation and/or for inducing apoptosis in plants comprising administering an effective amount of the composition of claim 1 to the plant.

In still another embodiment, this invention is a composition useful for treating fungal infections (fungi) in humans, animals and plants.

Diubstituted pyrazolo [4,3-d] pyrimidine derivatives result in the acquisition of extremely high potency against viruses on the part of the defined compounds. An important aspect of the present invention is a method for inhibiting proliferation of a DNA virus dependent upon events associated with cell proliferation for replication.

The DNA virus includes any of the retrovirus family. The efective amount is that sufficient to inhibit cellular CDK activity to extent impending viral replication.

In addition to other CDK1-related kinases, this kinase controls certain steps of cell division cycles, in particular the transition from Gl phase into the S phase and in particular the transition from the G2 phase into the M-phase. Out the basis of this findings, it can be expected that the compounds of the formula I and their acceptable salts can be used as antimitotic compounds and for treatment of proliferative diseases.

In addition to therapeutic applications it will be apparent the subject compounds can be used as a cell culture additive for controlling proliferative and/or differentiation states of cells in vitro, for instance, by controlling the level of activation of a CDK. By preventing the activation of a Go/Gl CDK, the subject inhibitors can prevent mitotic progression and hence provide a means for ensuring an adequately restrictive environment in order to maintain cells at various stages of differentiations, and can be employed, for instance, in cell cultures designed to test the specific activities of trophic factors. Other tissue culture systems which require maintenance of differentiation will be readily apparent to those skilled in the art.

It is likely that inhibition by the compounds, of the invention of the catalytic activity of cyclin-dependent kinases in mediated by interaction of the compounds at the ATP-binding site of the enzyme. Such compounds are particularly desirable for reducing excessive cell growth, since they allow inhibition of the kinase activity regardless of the cause underlying the excessive kinase activity leading to excessive cell proliferation. Thus, the compounds of the invention are active in situations in which the excessive kinase activity results from the kinase being a mutated hyperactive, form of the kinase and situations in which the kinase is present at excessive levels. Such compounds can also block excessive kinase activity in situations in which the cyclin regulating the kinase is present at excessive levels or its binding to the kinase is enhanced. Furthermore, compounds which block kinase activity by interacting with the ATP binding site of the enzyme are also useful for inhibiting kinase activity in situations in which a natural inhibitor of cyclin-kinase complexes is mutated.

It will also be aparent that differential screening assays can be used to select for those compounds of the present invention with specificity for CDK enzymes.

Thus, compounds, which act specifically on eukaryotic pathogens, e. g. , are anti- fungal or anti-parasitic agents, can be selected from the subject of the inhibitors.

By way of illustration, the assays described in the art can be used to screen for agents which may ultimately be useful for inhibiting at leas one fungus implicated in such mycosis as aspergillosis, blastomycosis, chromoblastomycosis, coccidiomycosis, conidiosporosis, actinomycosis, penicilliosis, monoliasis, or sporotrichosis. For example, if the mycotic infection to which treatment is desired is aspergillosis, an assay as described above or in the appended examples can comprise comparing the relative effectiveness of a test compound on inhibiting a plant CDK enzyme with its effectiveness towards a CDK enzyme from yeast. Likewise, the differential screening assays can be used to identify anti-fungal agents which may have value in the treatment of aspergillosis by making use of the CDK genes cloned from yeast such as Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, or Apergillus terreus.

In yer another embodiment, certain of the subject CDK inhibitors can be selected on the basis of inhibitory specificity for plant CDK s relative to the mammalian enzyme. For example, a plant CDK can be sidposed in a differential

screen with one or more of the human enzymes to select those compounds of greatest selectivity for inhibiting the plant enzyme. Thus, the present invention specifically contemplates formulations of the subject CDK inhibitors for agricultural applications, such as in the form of a defoliant or the like.

PROCESSES FOR PREPARATION SCHEME 1: HOOC HOOC R3 process process B) C 0 0 0 - 0, Ny R3 II III IV ROOC ROOC process C process D N z R3 R3 V VI

process A: N2H4-H20/T=96°C process B: H2SO4g03 process C: ROH/HCI process D : RaNi + H2/CH30H+H20 ; Pd or Pt + H2/CH30H+CH3COOH ; SnCl2 ; S2042.

SCHEME 2: HOs N ROOC R3,, process G so O R3 II VIII ROOC process G NH - I I N H2Nw R3 VT

process E: NaNO2 / HCl in C2H5OH or N203 (g) process F: N2H4 H2O process G: Na2S2O4 / EtOAc+H2O SCHEME 3: HOOC process G fiv- IV r R3 IX process H Oh processI process M vi N N R3 X prowess process / SH N process , N R3 XIII

process G: Na2S204/EtOAc+H20 process H: formamide/reflux process 1 : formamidin acetate/ Et3N/ 2-ethoxyethanol/ 90°C process J: P2S5/pyridine/reflux process K: CH3I/ 1 M KOH process L: R7'NH2 or R7'ONa (K, Li) or R7'SNa (K, Li)) process M: SOCl2/CHCl3/DMF /T=80°C or POCI3 or POCl3 / PCl5 process N: R7'NH2 or R7'ONa (K, Li) or R7'SNa (K, Li))

In one approach the 3-isopropyl-7-substituted pyrazolo [4,3-d] pyrimidine of the formula I, wherein R7 substituents are defined above for a compound of the formula I, are prepared by reaction of 7-chloro-3-isopropylpyrazolo [4,3- d] pyrimidine with appropriate nucleophile as l) amine (amonium hydroxyde, hydrazine, hydroxylamine, benzylamine; 2-, 3-, 4-hydroxybenzylamine; dihydroxybenzylamine; 3-chloroaniline, etc. ) or 2) lithium (natrium, kalium) salt of alcohole or mercaptane. Preferably, the appropriate nucleophil reactant may be R7'- X-Y, wherein R7'-X-is as defined in claim 1 and Y is H. A nucleophil is reagent is able to attack a place in molecule with absence of electrons. An appropriate alkylating agent is a reagent which is source of carbo cations which which attack a place in a molecule with excess of electrons-preferentially free electron couples, usually oxygen, nitrogen and sulfur, such as R7'-Z, wherein R7'is as defined in claim 1 and Z is selected from halogen, toluensulfonate, and mesylate. 7-Chloro-3- isopropylpyrazolo [4,3-d] pyrimidine is disolved in chloroform and appropriate R7- NH2 or R7-O (Li, Na, K), or R7-S (Li, Na, K) (5-20 eq. ) was added. After heating for several hours, the reaction mixture is cooled and the 7-substituted-3- isopropylpyrazolo [4,3-d] pyrimidine is obtained.

In another approach the 3-ethyl substituted pyrazolo [4, 3-d] pyrimidine of the formula I, wherein R7 substituents are defined above for a compound of the formula I, are prepared by reaction of 7-chloro-3-ethylpyrazolo [4, 3-d] pyrimidine with appropriate nucleophile as l) amine (amonium hydroxide, hydrazine, hydroxylamine, benzylamine; 2-, 3-, 4-hydroxybenzylamine; dihydroxybenzylamine; 3- chloroaniline, etc. ) or 2) lithium (natrium, kalium) salt of alcohole or mercaptane.

7-Chloro-3-isopropylpyrazolo [4,3-d] pyrimidine is disolved in chloroform and appropriate R7-NH2 or k7'-O (Li, Na, K), or R7-S (Li, Na, K) (5-20 eq. ) was added.

After heating for several hours, the reaction mixture is cooled and the 7-substituted- 3-ethylpyrazolo [4,3-d] pyrimidine is obtained.

In yet another approach the 3-methyl substituted pyrazolo [4,3-d] pyrimidine of the formula I, wherein R7 substituents are defined above for a compound of the formula I, are prepared by reaction of 7-chloro-3-methylpyrazolo [4,3-d] pyrimidine with appropriate nucleophile as l) amine (amonium hydroxide, hydrazine,

hydroxylamine, benzylamine; 2-, 3-, 4-hydroxybenzylamine; dihydroxybenzylamine; 3-chloroaniline, etc. ) or 2) lithium (natrium, kalium) salt of alkohole or mercaptane. 7-Chloro-3-isopropylpyrazolo [4,3-d] pyrimidine is disolved in chloroform and appropriate R7-NH2 or R 7'-O (Li, Na, K), or R 7'_S (Li, Na, K) (5- 20 eq. ) was added. After heating for several hours, the reaction mixture is cooled and the7-substituted-3-methylpyrazolo [4, 3-d] pyrimidine is obtained.

Further, Fig. 1 shows a diagram displaying the specific inhibition of plant cdc2 kinase activity in plant cells. Enzyme activity bound to pl3'ucl-agarose was measured by phosphorylation of histone H1 substrate protein in the presence of various concentrations of (1) 7-furfurylamino-3-methylpyrazolo [4,3-d] pyrimidine, (2) 7-benzylamino-3-isopropylpyrazolo [4,3-d] pyrimidine, (3) 7- (3-chloroanilino)-3- isopropylpyrazolo [4,3-d] pyrimidine, (4) 7- (3-hydroxybenzyl) amino-3- isopropylpyrazolo [4,3-d] pyrimidine.

Fig. 2 shows pictures of the induction of aberrant mitosis in root meristem cells of IT faba after the treatment with 200 mM A2.16. 32, wherein pictures a-e-control cells pictures a'-e'-cells treated with 200 mM A2.16. 32 for 12 hr. picturre a-lower magnification shouwing frequency od mitosis (a), and aberrant mitosis (a'). b, b'-prophase, c, c'-metaphase, d, d'-anaphase, e, e'-telophase.

Fig. 3 shows immunofluorescence visualization of microtubules in control (A) and treated (B) root meristem cells of V. faba. Green-FITC immunolabelling for alfa- tubulin (left column), red-immunolabelling for gamma-tubulin (middle column), blue-immunolabelling for DNA labelling with DAPI (right column).

Fig. 4 shows pictures of the electrophoretic detection of double strand DNA breaks (marker of apoptosis) after the treatment of root meristem cells of Vicia faba with bohemine (200 uM) wherein the slots are 1. molecular weight markers 2. control I-DNA after 10 h incubation without the drug

3. DNA after 10 h incubation with bohemine 4. control II-DNA after 44 hod inkubation without the drug and 5. DNA pafter 44 hod incubation with bohemine.

Fig. 5 shows immunofluorescence detection of DNA double strand breaks in root meristem cells of V. faba treated with bohemine.

A. Root meristem cells of V. faba, treated with bohemine (200 mM). IS. line B. Control cells. 2nd. line 1. column-FITC labelling of DNA breaks.

2. column-DAPI labelling for chromatin 3. column-merged images of FITC and DAPI The following EXAMPLES serve to illustrate the invention without limiting the scope thereof.

The starting material for the compounds of the formula I is available from commercial sources (Sigma, Aldrich, Fluka, etc. ). Melting points were determined on a Koffler block and are uncorrected. Evaporations were carried out on a rotary evaporator under vacuum at temperatures below 80°C. The lH NMR spectra (cy, ppm; J, Hz) were measured on Varian VXR-400 (400MHz) or on Varian Unity 300 (400MHz) instruments. All spectra were obtained at 25°C using tetramethylsilane as on a internal standard. Electron impact mass spectra m/z (rel. %, composition, deviation) were measured on a VG 7070E spectrometer (70eV, 200°C, direct inlet).

Quadrupole mass spectra were measured on a Micromass ZMD detector with electrospray ionization. Merck silica gel Kieselgel 60 (230-400 mesh) was used for column chromatography. All compounds gave satisfactory elemental analyses (0, 4%).

EXAMPLE 1: methyl 2, 4-dioxo-5-methylhexenoate (II) : Prepared according to : E. Royals: J. Am. Chem. Soc. 67,1508 (1945)

EXAMPLE 2: 5-isopropylpyrazol-3-carboxylic acid (III) A solution of methyl 2, 4-dioxo-5-methylhexenoate II (31g ; 180 mmol) and N2H4 H20 (13mL, 180 mmol) in ethanol (120 mL) was refluxed for 2 hours. The mixture was poured into H20 and extracted with chloroform. The chloroform extract was concentraded under reduced pressure to give a yellow liquid. The liquid and aq.

3 M NaOH (120 mL) was stirred overnight at room temperature. The acidification of the yellow solution to pH=2 with conc. HCl affords crystals. Crystals were filtered off and washed with ice-water. Yield 68%, mp=136-140°C.

'H NMR (300MHz, MeOD) : 1.14d (6H, 7. lHz), 3.02sept. (1H, 7. lHz), 6.59s (1H). ; CHN required: C=54.54% ; H=6.54% ; N=18.17% ; found: C=54.58% ; H=6.38% ; N=18. 12%.

EXAMPLE 3: 5-isopropyl-4-nitropyrazole-3-carboxylic acid (IV) : To an ice-cooled and stirred solution of 2.9g (18. 8mmol) 5-isopropylpyrazol-3- carboxylic acid III in fuming sulphuric acid 1 mL (65%, ), sulphuric acid 7.6 mL (100%) and the nitric acid 3 mL (65%) was added portionwise. The stirring was continued for lh at room temperature and then another 3h at 104°C temperature and then poured into ice-water. The white precipitate of product was filtered and crystallized from water; (yield 76%); mp=139-142°C ;'H NMR (300MHz, DMSO): 1.22d (6H, 7. lHz), 2.94sept (1H, 7. lHz), 3.33s (1H), 6.45bs (1H) ; CHN required: C=42.02% ; H=4.56% ; N=21.09% ; found: C=42.41% ; H=4.49% ; N=21.01%.

EXAMPLE 4: Methyl 5-isopropyl-4-nitropyrazol-3-carboxylate (V) 5-Isopropyl-4-nitropyrazole-3-carboxylic acid was added to a 4. 5M solution of HCl in absolute methanol. The reaction mixture was heated at 60°C for 7 hours and then was evaporated to dryness. The title compound was crystallised from ethyl acetate; yield 91%; mp=78-80°C.'H NMR (300MHz, CDC ) : 1.39d (6H, J=7. lHz) ; 3.64sept (1H, J=7. lHz), 3. 98s (3H). CHN required: C=45. 07%; H=5.20% ; N=19. 70%

; found : C=45.21% ; H=5. 23% ; N=19.65%.

EXAMPLE 5: Methyl 4-amino-5-isopropylpyrazol-3-carboxylate (VI) mode A To a solution of methyl 5-isopropyl-4-nitropyrazol-3-carboxylate (4.34g, 24 mmol) in 20 mL ethanol and 5 mL water was added lg RaNi (an activity W5). The mixture was stirred under hydrogen atmosphere (760 Torr) for 12 hours. The RaNi was filtered off and the filtrate was concenrated in vacuo. The residue crystals were washed with cooled ethylacetate; yield 95%; mp=122-123°C. MS (EI, 70eV, direct inlet): 183 (88; CsH13N302+ ; -1. 0), 168 (59), 152 (3), 136 (100), 108 (8), 80 (16), 68 (20). lH NMR (400MHz, CDCl3) : 1. 31d (6H; J=6.9Hz), 2.93sept (1H ; J=6.9Hz), 3.9s (3H). IR (KBr, cm-1) : 3399,3296, 1710,1626, 1584,1302. mode B To a solution of methyl 4-nitropyrazol-3-carboxylate V (7.34g, 34. 4mmol) in 36 mL n-propanole, 6 mL water and 5.6 mL 10 M HCI was added 0. 55g PtO2. The mixture was stirred under hydrogen atmosphere (760 Torr) for 9 hours. The reaction mixture was filtered and the filtrate was concentrated to dryness in vacuo. The desired amine was liberated by treatment of aq. ammonia during extraction into chloroform.

The product crystallised after evaporation; yield 95%; mp=122-123°C.

EXAMPLE 6: 7-hydroxy-3-isopropylpyrazolo [4,3-d] pyrimidine (X) A mixture of aminoester VI (1.5 g, 8.42 mmol), formamidine acetate (2.47 g, 24 mmol) and triethylamine (5,25 mL) in 32 mL of 2-ethoxyetanol was heated for 2 hours at 90°C under argon atmosphere. The excess of triethylamine was evaporated from cellosolve solution in vacuo, the crystallised product was filtered off and washed with chloroform. An analytical sample was obtained by recrystallisation from ethanol. Yield 96%; mp=302-304°C.'H-NMR (300MHz, CD30D) : 1. 41d (6H, J=7.15Hz), 3.40sept (1H, J=7.15Hz), 7.82s (1H). 13C-NMR (400MHz, DMSO-d6+AcOD) : 21.912, 25.985, 141.85, 172.17. CHN required: C=53.92% ; H=5. 66%; N=31.44 ; found: C=53.20% ; H=5.58% ; N=31.39%. MS (El) : 178 (35;

CgHIoN40+) ; 177 (8) 163 (25;C7H7N4O#+); 150(18;C6H6N4O#+) ; 54 (18); 53 (10); 41 (11) ; 28 (38) ; 27 (11).

EXAMPLE 7: [7-chloro-3-isopropylpyrazolo [4,3-d] pyrimidine (XI)] 7-Hydroxy-3-isopropylpyrazolo [4, 3-d] pyrimidine X (200 mg, 1.122 mmol) was dissolved in the mixture of 0.81 mL (11 mmol) of thionyl chloride, 0.12 mL (1. 56 mmol) of dimethylformamide and 5 mL of chloroform. This mixture was heated under reflux for 3 hours. The solution was evaporated to dryness in vacuo and the residue was dissolved in chloroform. This solution was extracted twice with a small portions of water and combined chloroform extract was dried over Na2SO4. This compound VIII was not isolated and was used immediately as chloroform solution in following reaction step.

EXAMPLE 8: 7-benzylamino-3-isopropylpyrazolo [4,3-d] pyrimidine XIIa To chloroform solution of XI (prepared in the subsequent step from 200 mg X) was added 3 mL of benzylamine. This mixture was stirred at room temperature 10 minutes and then evaporated to dryness in vacuo. The crude product was purified by columm chromatography on silica gel, the mixture of chloroform/methanol (98. 5/ 1.5) was used as mobile phase. Yield 82%; mp=153-154°C. 1H-NMR (400MHz, CDC13) : 1.40d (6H, J=7.02Hz) ; 3.41sept (1H, J=7.02Hz) ; 4.80s (2H), 7.25m (5H), 6.57s (1H), 8.4s (1H). CHN required: C=67.39% ; H=6.41% ; N=26.20 ; found: C=67.33% ; H=6. 43%; N=26.24%. MS (EI) : 267 (62 ; CgHioN40- ; 266 (18) 252 (44); 239 (6); 106 (49); 91 (100); 65 (21); 43 (14); 41 (16).

EXAMPLE 9: 7- (2-hydroxybenzyl) amino-3-isopropylpyrazolo [4, 3-d] pyrimidine XIIb To chloroform solution of XI (prepared in the subsequent step from 200 mg X) was added 1.31 mL (7.7 mmol) N-ethyldiisopropylamine, 3 mL EtOH and 500 mg (4.06 mmol) 2-hydroxybenzylamine. This mixture was heated one hour at 60°C and then

was evaporated to dryness in vacuo. The crude product was purified by chromatography on silica gel in the mixture of chloroform/methanol/AcOH (20: 0.4 : 0.1). Yield 40%; mp=214-217°C.'H-NMR (400MHz, DMSO-d6) : 1.36d (6H, J=6.96Hz) ; 3.28sept (1H, J=6.96Hz) ; 4.65s (2H), 6.78-7. 26m (4H), 8.21s (1H). CHN required: C=63.59% ; H=6.05% ; N=24.72 ; found: C=63. 39%; H=6.07% ; N=24.62%. MS (ES): [M+H] +=274. 3 (100).

EXAMPLE 10: 7- (3-hydroxybenzylamino)-3-isopropylpyrazolo [4,3-d] pyrimidine XIIc To chloroform solution of XI (prepared in the subsequent step from 200 mg X) was added 1.5 mL (8.8 mmol) N-ethyldiisopropylamine, 5 mL EtOH and 500 mg (4.06 mmol) 3-hydroxybenzylamine. This mixture was heated one hour at 60°C and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel in the mixture of chloroform/methanol/AcOH (20: 0.6 : 0.1). Yield 48% ; mp=220-221°C. 1H-NMR (300MHz, DMSO-d6) : 1.38d (6H, J=7.14Hz) ; 3.26sept (1H, J=7.14Hz) ; 4.68s (2H), 6.62-7. 17m (3H), 8.22s (1H) ; 9. 31s (lH). MS (ES): [M+H] +=274. 3 (100).

EXAMPLE 11: 7- (4-hydroxybenzyl) amino-3-isopropylpyrazolo [4,3-d] pyrimidine XIId To chloroform solution of XI (prepared in the subsequent step from 200 mg X) was added 1.5 mL (8.8 mmol) N ethyldiisopropylamine, 5 mL EtOH and 500 mg (4.06 mmol) 4-hydroxybenzylamine. This mixture was heated one hour at 60°C and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel in the mixture of chloroform/methanoUAcOH (20: 1: 0.1). Yield 49%; mp=234-236°C.'H-NMR (300MHz, DMSO-d6) : 1.28d (6H, J=6.59Hz) ; 3.58sept (1H, J=6.59Hz) ; 4.60s (2H), 6.73-7. 21m (4H), 8.20s (1H). MS (ES): [M+H] +=274. 3 (100).

EXAMPLE 12: 7- (3-chloroanilino)-3-isopropylpyrazolo [4, 3-d] pyrimidine XIIe

To chloroform solution of XI (prepared in the subsequent step from 200 mg X) was added 1.20 ml (11.2 mmol) 3-chloroaniline. This mixture was heated one hour at 60°C, then was cooled at room temperature and crystals were precipitated. These colourless crystals were washed with ether; the analytical sample was obtained by recrystallisation from mixture ethanol-ether. Yield 58%; mp=213-216°C. IH-NMR (400MHz, DMSO-d6) : 1.40d (6H, J=6.94Hz) ; 3.48sept (1H, J=6.94Hz) ; 7.30dd (1H), 7.49dd (1H), 7.86dd (1H), 8.20s (1H), 8.78s (1H). CHN (cl4Hl4Nscl HCl H2O) required: C=49.20% ; H=5.01% ; N=20.48% ; Cl=20. 48%; found: C=49.43% ; H=5. 09%; N=20.13% ; Cl=20. 58%. MS (ES): [M+H] +=288. 5 (100), 290.5 (33).

EXAMPLE 13: 7- (isopent-2-en- (1-yl) amino)-3-isopropylpyrazolo [4,3-d] pyrimidine XIIf To chloroform solution of XI (prepared in the subsequent step from 200 mg X) was added 3.5 mL (20 mmol) N-ethyldiisopropylamine, 3 mL EtOH and 620 mg (4.7 mmol) isopent-2-en-l- (yl) amino hydrochloride. This mixture was stirred 12 hours at room temperature and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel in the mixture of chloroform/methanol/aq. NH40H (98: 2: 1). Yield 48%; syrupy.'H-NMR (400MHz, CDCl3) : 1.45d (6H, J=6.96Hz) ; 1.65d (1H, J=1. 28Hz), 3.47sept (1H, J=6.96Hz) ; 4.18d (2H, J=1.28Hz), 5.25m (1H, J=1.28Hz), 6.25s (1H), 8.22s (1H).

COSY [1. 45d (6H, J=6. 96Hz); 3.47sept (1H, J=6.96Hz)], COSY [1. 65d (6H, J=1.28Hz) ; 4.18d (2H, J=1.28Hz) ; 5.25m (1H, J=1.28Hz)], COSY [4.18d (2H); 6.25s (1H)]. MS (ES): [M+H] +=246. 5 (100).

EXAMPLE 14: 7-furfurylamino-3-isopropylpyrazolo [4,3-d] pyrimidine XIIg To the chloroform solution of XI (prepared in the subsequent step from 150 mg X) was added 2 mL (0.205 mol) furfurylamine. This mixture was stirred 1 hour at 50°C and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel in the mixture of chloroform/methanol/aq.

NH4OH (98: 2: 0.2). Yield 43%; mp=179-182°C.'H-NMR (500MHz, MeOD) :

1.422d (6H, J=7. 0Hz) ; 3.455sept. (1H, J=7. 0Hz) ; 4.802s (2H); 6.373s (2H) ; 7.468s (1H) ; 8.273s (1H). MS (ES) : [M+H] +=258. 3 (100).

EXAMPLE 15: 7-pentylamino-3-isopropylpyrazolo [4,3-d] pyrimidine XIIh To the chloroform solution of XI (prepared in the subsequent step from 150 mg X) was added 0.29 mL (2.53 mmol) 3-pentylamine. This mixture was stirred 1 hour at 50°C and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel. in the mixture of chloroform/methanol (99: 1). Yield 25%; mp=73-75°C. IH-NMR (500MHz, MeOD) : 0.933t (3H, J=7. 0Hz) ; 1.374bs (2H); 1.388bs (2H) ; 1.418d (6H, J=6.9Hz) ; 1.715pent. (2H, J=7. 0Hz), 3.447hept. (1H, J=6.9Hz) ; 3.583t (2H, J=7. 0Hz) ; 8.207s (1H). MS (ES): [M+H] +=248. 2 (100).

EXAMPLE 16: 7-(2-bromobenzyl)amino-3-isopropylpyrazolo [4,3-d] pyrimidine XIIk To chloroform solution of XI (prepared in the subsequent step from 152 mg X, 0.855 mmol) was added 0.44 mL (2.60 mmol) N-ethyldiisopropylamine, 2 ml methanol and 343 mg (1.54 mmol) 2-bromobenzylamine hydrochloride. This mixture was heated two hours at 60°C and then was evaporated to dryness in vacuo.

The crude product was purified by column chromatography on silica gel in the mixture of chloroform/methanol (98.5 : 1.5) crystallization from Et20. Yield 42%; mp=194-196°C.'H-NMR (300MHz, CH30D) : 1.44d (6H, J=6.9Hz) ; 3.43hept (1H, J=6.9Hz) ; 4.89s (2H); 7.20t (1H, J=7. lHz) ; 7.32t (1H, J=7. lHz) ; 7.45bs (1H) ; 7.62d (1H, J=7. 1Hz) ; 8.24s (1H). MS (ES): [M+H] +=246. 2 (95), 248.2 (100).

EXAMPLE 17: 7- (4-methoxybenzyl) amino-3-isopropylpyrazolo [4, 3-d] pyrimidine XII I To chloroform solution of XI (prepared in the subsequent step from 152 mg X, 0.855 mmol) was added 0.34 mL (2.60 mmol) 4-methoxybenzylamine. This mixture was heated one hour at 52°C and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel in the mixture

of chloroform/methanol (98: 2), crystallization from Et20. Yield 42%; mp=143- 144°C. 1H-NMR (300MHz, CDCl3) : 1.36d (6H, J=6. 9Hz); 3.46sept. (1H, J=6. 9Hz) ; 3.69s (3H), 4.86bs (2H) ; 6.72d (2H, J=8.8Hz) ; 7.30d (2H, J=8.8Hz) ; 8.34s (1H).

MS (ES) : [M+H] +=298. 3 (100).

EXAMPLE 18: 7- (3-hydroxy-4-methoxybenzyl) amino-3-isopropylpyrazolo [4, 3-d] pyrimidine XIIm To chloroform solution of XI (prepared in the subsequent step from 152 mg X, 0.855 mmol) was added 0.44 mL (2.60 mmol) N-ethyldiisopropylamine, 7 mL methanol and 236 mg (1.54 mmol) 3-hydroxy-4-methoxybenzylamine. This mixture was heated one hour at 52°C and then was evaporated to dryness in vacuo. The crude product was purified by column chromatography on silica gel in the mixture of chloroform/methanol/NH4OH (93.5 : 6.5 : 0.1) crystallization from chloroform/Et20. Yield 62%; mp=197-199°C.'H-NMR (300MHz, CH30D) : 1.43d (6H, J=7.15Hz) ; 4.45hept (1H, J=7.15Hz) ; 3.83s (3H) ; 4.67s (2H), 6. 82-6. 90m (3H), 8.24s (1H). MS (ES): [M+H] +=314. 3 (100).

Table 1: Compounds Prepared by the Method of Examples 8-18 PYRAZOLO [4,3-d] PYRIMIDINE CHN MS SUBSTITUENT ANALYSES ANALYSES-ZMD C7 C3 [%] [M-H]- a) [M+H]+ b) 1 3-chloroanilino methyl C=55.50 ; H=3. 88 260. 1 N=26. 97 ; CI=13. 65 262. 1 2 anilino methyl C=63. 99; H=4. 92 226. 1 N=31.09 3 4-bromoanilino methyl C=47.39 ; H=3. 31 303. 0 304, 0 N=23.03 ; Br=26. 27 305.0 306.0 4 4-chloroanilino methyl C=55.50 ; H=3.88 260.1 N=26. 97 ; CI=13. 65 262. 1 5 2-hydroxybenzylamino methyl C=61.17 ; H=5. 13 254. 1 256. 1 N=27. 43 6 3-hydroxybenzylamino methyl C=61.17 ; H=5. 13 254. 1 256. 1 N=27. 43 7 4- hydroxybenzylamino methyl C=61. 17 ; H=5. 13 254. 1 256. 1 N=27. 43 8 2-methylbenzylamino methyl C=66.8 ; H=5.79 254. 1

N=27. 65 9 3-methylbenzylamino methyl C=66.38 ; H=5.79 254.1 N=27.65 10 4-methoxybenzylamino methyl C=62. 44; H=5. 61 270. 0 N=26.00 11 2-chlorobenzylamino methyl C=57.04 ; H=4.42 274.1 N=25. 59; Cl=12. 95 276.1 12 2-bromobenzylamino methyl C=49. 08; H=3. 80 319. 0 N=22. 01; Br=25. 11 321.0 13 3-chlorobenzylamino methyl C=57. 04; H=4. 42 274. 1 N=25.59 ; Cl=12. 95 276.1 14 3-hydroxy-4-methoxybenzylamino methyl C=58.94 ; H=5. 30 286. 0 N=24.55 15 furfurylamino methyl C=57. 63 ; H=4. 84 230.1 N=30.55 16 allylamino methyl C=57. 13 ; H=5. 86 190. 1 N=37.01 17 cyclohexylamino methyl C=62.31 ; H=7.41 232.2 N=30.28 18 1,4-(trans)-cyclohexyldiamino methyl C=58.52;H=7.37 247. 0 N=34.12 19 1, 2- (cis)-cyclohexyldiamino methyl C=58. 52; H=7. 37 247. 0 N=34.12 20 cyclopentylamino methyl C=60.81;H=6.96 218. 1 N=32.23 21 cyclobutylamino methyl C=59. 10 ; H=6.45 204.1 N=34.46 22 (isopent-2-en-1-yl) amino methyl C=60. 81 ; H=6.96 204.1 N=32.23 23 pentylamino methyl C=60.25;H=7.81 220. 0 N=31.94 24 4-chlorobenzylamino methyl C=57.04 ; H=4.42 274.1 N=25. 59 ; CI=12. 95 276. 1 a) solution: MeOH p. a. + HCOOH b) solution : MeOH p. a. + H20 + NH3 Table 2: Compounds Prepared by the Method of Examples 8-18 PYRAZOLO [4,3-d] PYRIMIDINE CHN MS SUBSTITUENT ANALYSES ANALYSES-ZMD C7 C3 [%] [M-H]- a) [M+H]+ b) 25 3-chloroanilino ethyl C=57. 04; H=4. 42 274. 1 N=25.59; Cl=12.95 276.1 26 anilino ethyl C=65.26;H=5.48 240. 1 N=29. 27 27 4-bromoanilino ethyl C=49.07 ; H=3. 80 317. 0 318. 0 N=22. 01 ; Br=25. 11 319.0 320.0 28 4-chloroanilino ethyl C=57.04 ; H=4. 42 274. 1 N=25. 59;Cl=12. 95 276.1 29 2-hydroxybenzylamino ethyl C=62. 44; H=5. 61 268. 1 270. 1 N=26.00 30 3-hydroxybenzylamino ethyl C=62.44 ; H=5.61 268. 1 270. 1 N=26.00 31 4- hydroxybenzylamino ethyl C=62.44 ; H=5. 61 268. 1 270. 1 N=26.00 32 2-methylbenzylamino ethyl C=67. 39; H=6. 41 268. 2 N=26. 20 33 3-methylbenzylamino ethyl C=67.39 ; H=6. 41 268. 2 N=26. 20 34 4-methoxybenzylamino ethyl C=63.59 ; H=6. 05 284. 0 N=24. 72 35 2-chlorobenzylamino ethyl C=58.44 ; H=4.90 288. 1 N=24. 34; Cl=12. 32 290. 1 36 2-bromobenzylamino ethyl C=50. 62; H=4. 25 333.0 N=21.08 ; Br=24. 05 335.0 37 3-chlorobenzylamino ethyl C=58. 44; H=4.90 288.1 N=24.34; Cl=12. 32 290.1 38 3-hydroxy-4-methoxybenzylamino ethyl C=60.19 ; H=5.72 300.0 N=23. 40 39 furfurylamino ethyl C=59. 25; H=5. 39 244. 1 N=28.79 40 allylamino ethyl C=59. 10; H=6. 45 204. 1 N=34. 46 41 cyclohexylamino ethyl C=63.65 ; H=7. 81 246. 2 N=28. 55 42 1, 4-(trans)-cyclohexyldiamino ethyl C=59.98;H=7.74 261.0 N=32. 28 43 1, 2- (cis)-cyclohexyldiamino ethyl C=59. 98; H=7. 74 261. 0 N=32.28 44 cyclopentylamino ethyl C=62.31 ; H=7.41 232.2 N=30. 28 45 cyclobutylamino ethyl C=60.81; H=6. 96 218.1 N=32. 23 46 (isopent-2-en-1-yl) amino ethyl C=62.31; H=7. 41 232. 2 N=30. 28 47 pentylamino ethyl C=61. 78; H=8.21 234. 0 N=30.02 48 4-chlorobenzylamino ethyl C=58.44;H=4.90 288. 1 N=24. 34 ; Cl=12. 32 290. 1 a) solution: MeOH p. a. + HCOOH b) solution: MeOH p. a. + H20 + NH3 Table 3: Compounds Prepared by the Method of Examples 8-18 PYRAZOLO [4,3-d] PYRIMIDINE CHN MS SUBSTITUENT ANALYSES ANALYSES-ZMD C7 C3 [%] [M-H]- a) [M+H]+ b) 49 3-chloroanilino isopropyl C=58,44; H=4,90 288.5 N=24,34 ; Cl=12, 32 290.5 50 anilino isopropyl C=66, 38 ; H=5,97 254.1 N=27, 65 51 4-bromoanilino isopropyl C=50.62 ; H=4. 25 331. 1 332. 1 N=21.08 ; Br-24. 05 333.1 334.1 52 4-chloroanilino isopropyl C=58, 44 ; H=4, 90 286. 1 288. 1 N=24, 34 ; CI=12, 32 288.1 290.1 53 2-hydroxybenzylamino isopropyl C=63 59 ; H=6. 05 272. 3 274.3 N=24.72 54 3-hydroxybenzylamino isopropyl C=63.59 ; H=6.05 272. 3 274. 3 N=24.72 55 4-hydroxybenzylamino isopropyl C=63. 59 ; H=6. 05 272. 3 274. 3 N=24.72 56 2-methylbenzylamino isopropyl C=68. 30 ; H=6.81 282.2 N=24. 89 57 3-methylbenzylamino isopropyl C=68. 30 ; H=6. 81 282.2 N=24. 89 58 4-methoxybenzylamino isopropyl C=64.63 ; H=6.44 296.3 298.3 N=23.55 59 2-chlorobenzylamino isopropyl C=59.70 ; H=5. 34 302.1 N=23. 21; Cl=11. 75 304.1 60 2-bromobenzylamino isopropyl C=52.04 ; H=4.66 344.1 346.1 N=20. 23 ; CI=23. 08 346.1 348. 1 61 3-chlorobenzylamino isopropyl C=59.70 ; H=5.34 302.1 N=23. 21; Cl=11. 75 304.1 62 3-hydroxy-4-methoxybenzylamino isopropyl C=61. 33 ; H=6.11 312.3 314. 3 N=22.35 63 furfurylamino isopropyl C=60.69 ; H=5. 88 258. 3 N=27.22 64 allylamino isopropyl C=60.81 ; H=6. 96 218.1 N=32. 23 65 cyclohexylamino isopropyl C=64.84 ; H=8.16 260.2 N=27.00 66 I, 4- (trans)-cyclohexyldiamino isopropyl C=61. 29 ; H=8.08 273.3 275.3 N=30. 63 67 1, 2- (cis)-cyclohexyldiamino isopropyl C=61. 29; H=8. 08 273. 3 275. 3 N=30. 63 68 cyclopentylamino isopropyl C=63.65 ; H=7. 81 246.2 N=28.55 69 cyclobutylamino isopropyl C=62. 31 ; H=7.41 232.2 N=30.28 70 isopent- (2-en)-1-ylamino isopropyl C=63.65 ; H=7.81 246. 5 N=28.55 71 pentylamino isopropyl C=63.13 ; H=8. 56 248.2 N=28.31 72 4-chlorobenzylamino isopropyl C=59.70 ; H=5. 34 302.1 N=23. 21 ; Cl=11. 75 304.1

a) solution: MeOH p. a. + HCOOH b) solution: MeOH p. a. + H20 + NH3 EXAMPLE 19: CDK Inhibition Assays Proteins Cyclin-dependent kinases (p34cdc2, p33") and cyclins (cyclin B, E) are produced in Sf9 insect cells coinfected with appropriate baculoviral constructs. The cells are harvested 68-72 hrs post infection in lysis buffer for 30 min on ice and the soluble fraction is recovered by centrifugation at 14.000 g for 10 min. The protein extract is stored at-80 °C.

Lysis buffer: 50mM Tris pH 7.4, l50mM NaCl, 5mM EDTA, 20mM NaF, 1% Tween, ImMDTT, O. lmMPMSF, leupeptine, aprotonine.

Enzyme inhibition assays To carry out experiments on kinetics under linear conditions, the final point test system for kinase activity measurement is used. The kinase is added to reaction mixture in such a way as to obtain linear activity with respect to the concentration of enzyme and with respect to time.

The p34Cdc2 and p33cdk2 kinase inhibition determination involves the use of lmg/ml histone H1 (Sigma, type III-S) in the presence of 15 µM [γ-33P] ATP (500- 100 cpm/pmol) (ICN) in a final volume of 10 1ll. Kinase activity is determined at 30 °C in the kinase buffer.

Tested compounds are usually dissolved to 100 mM solutions in DMSO, final concentration of DMSO in reaction mixture never exceeds 1%. The controls contain suitable dilutions of DMSO.

After 10 min, addition 3x SDS sample buffer stops the incubations.

Phosphorylated proteins are separated electrophoretically using 10 % SDS polyacrylamide gel. The measurement of kinase activity is done using digital image analysis.

The kinase activity is expressed as a percentage of maximum activity, the apparent inhibition constants are determined by graphic analysis.

Kinase buffer: 50 mM Hepes pH 7.4, 10 mM MgC12, 5 mM EGTA, 10 mM 2-glycerolphosphate, 1 mM NaF, 1 mM DTT Table 4: Kinase Inhibitory Activity of Selected 3, 7-Disubstituted Pyrazolo [4,3- d] pyrimidine Derivatives SUBSTITUENT CDK1 CDK2 C7 C3 IC50 (M) IC50 (µM) Olomoucine 7 7 3-chloroanilino methyl 14 16 anilino methyl 22 21 3-chloro-5-aminoanilino methyl 19 24 3-chloro-4-carboxyanilino methyl 25 28 3-carboxy-4-chloroanilino methyl 24 29 3-carboxy-4-hydroxyanilino methyl 34 40 4-bromoanilino methyl 16 18 4-chloroanilino methyl 26 28 3-amino-4-chloroanilino methyl 27 28 3-chloro-4-aminoanilino methyl 26 28 2-hydroxybenzylamino methyl 5. 2 3-hydroxybenzylamino methyl 5.5 7.2 2-methylbenzylamino methyl 18 17 3-methylbenzylamino methyl 28 31 2-chlorobenzylamino methyl 25 24 3-chlorobenzylamino methyl 8.8 9.4 furfurylamino methyl 18 16 allylamino methyl 42 48 cyclohexylamino methyl 34 32 cyclopentylamino methyl 29 46 cyclobutylamino methyl 35 28 isopentenylamino methyl 45 44 4-chlorobenzylamino methyl 20 benzylamino ethyl 12 11 3-chloroanilino ethyl 24 18 anilino ethyl 14 20 3-chloro-5-aminoanilino ethyl 20 15. 5 3-chloro-4-carboxyanilino ethyl 36 32 3-carboxy-4-chloroanilino ethyl 38 40 3-carboxy-4-hydroxyanilino ethyl 24 22 4-bromoanilino ethyl 22 18 4-chloroanilino ethyl 14 16 3-amino-4-chloroanilino ethyl 23 22 3-chloro-4-aminoanilino ethyl 35 28 2-hydroxybenzylamino ethyl 6. 2 7 3-hydroxybenzylamino ethyl 6 3. 2 2-methylbenzylamino ethyl 15 14 3-methylbenzylamino ethyl 18 17 2-chlorobenzylamino ethyl 12 12 3-chlorobenzylamino ethyl 9. 7 10. 2 furfurylamino ethyl 8. 2 5. 3 allylamino ethyl 25 29 cyclohexylamino ethyl 39 42 cyclopentylamino ethyl 32 32 cyclobutylamino ethyl 27 25 isopentenylamino ethyl 45 41 4-chlorobenzylamino ethyl 26 19 benzylamino isopropyl 1. 3 0.5 3-chloroanilino isopropyl 2.0 0.8 anilino isopropyl 4.4 5,2 3-chloro-5-aminoanilino isopropyl 6. 1 5. 8 3-chloro-4-carboxyanilino isopropyl 2. 5 2. 8 3-carboxy-4-chloroanilino isopropyl 2. 8 2. 9 3-carboxy-4-hydroxyanilino isopropyl 3. 1 4.2 4-bromoanilino isopropyl 1.7 1.9 4-chloroanilino isopropyl 2.1 3.1 3-amino-4-chloroanilino isopropyl 2.9 3.0 3-chloro-4-aminoanilino isopropyl 2.9 3.0 2-hydroxybenzylamino isopropyl 0,4 0,27 3-hydroxybenzylamino isopropyl 1,1 0. 9 4-hydroxybenzylamino isopropyl 1. 8 0. 2 4-methoxybenzylamino isopropyl 2 3 1. 0 2-methylbenzylamino isopropyl 2 1. 4 3-methylbenzylamino isopropyl 2.2 3.1 2-chlorobenzylamino isopropyl 2. 1 2.0 3-chlorobenzylamino isopropyl 8. 8 9.4 3-hydroxy-4-methoxy isopropyl 0,9 0,2 2-bromobenzylamino isopropyl 7 9 furfurylamino isopropyl 1,8 0,8 allylamino isopropyl 16 14 cyclohexylamino isopropyl 80 95 cyclopentylamino isopropyl 18 20 (2-aminocyclohexyl) amino isopropyl >100 >100 (4-aminocyclohexyl) amino isopropyl 80 70 pentylamino isopropyl 1, 7 1. 4 isopentenylamino isopropyl 4. 5 1. 3 4-chlorobenzylamino isopropyl

Table 4 shows the results of inhibitory activity of novel compounds against CDK1 and CDK2 in comparison with the data on a prototype compound (trisubstituted purine olomoucine). Most of the 3,7-disubstituted pyrazolo [4,3-d] pyrimidine derivatives showed marked inhibitory activity in in vitro kinase assays EXAMPLE 20: CDK Inhibitory Activity on Plant Kinases and Antimitotic Effects Protein extraction and purification of pant CDK by binding to pl3''"-beads or immunopurification with an antibody specific to the cdc2a-MS protein was carried out as described previously (Bogre et al 1997, Plant Physio. 113,1997, 841-852). The MMK1 protein kinase was purified with a specific antibody from Vicia faba extracts as described by Bigre te al. 1997a, Plant Cell 9,75-83). Protein kinase activity was measured as described above in Example 19. The quantification of radioactivity incorporated into histone H1 or myelin basic protein was undertaken using Phosphoimager (original gel images shown on Fig. 1). ICso were calculated from dose-response curves. The drugs inhibited the activity of immunopurified Vicia faba and alfalfa Cdc2-kinase. An observed transient arrest at the G1/S and G2/M indicated that inhibition of the Cdc2-kinase had an effect on both transitions. In contrast to the regular bipolar spindle in untreated cell, in drug-treated metaphase cells abnormally short and dense kinetochore microtubule fibres were observed.

These microtubules were randomly arranged in the vicinity of the kinetochores and connected the chromosomes. Thus the chromosomes were not aligned on the metaphase plate but were arranged in a circle, with kinetochores pointing inwards and chromosome arms pointing outwards. y-tubulin, which plays a role in microtubule nucleation, also localised to the centre of the monopolar spindle. The observed abnormalities in mitosis, after inhibition of Cdc2-kinase by specific drugs

suggest a role for this enzyme in regulating some of the steps leading to a bipolar spindle structure (Fig. 2 and 3).

Table 5: Kinase Inhibitory Activity of Selected 3,7-Disubstituted Pyrazolo [4,3- d] pyrimidine Derivatives SUBSTITUENT CDC2a MMKI C7 C3 IC50 (µM) IC50(µM) Olomoucine 8 15. 4 3-chloroanilino methyl 10 9. 6 anilino methyl 3-chloro-5-aminoanilino methyl 21 24 3-chloro-4-carboxyanilino methyl 27 29 3-carboxy-4-chloroanilino methyl 25 30 3-carboxy-4-hydroxyanilino methyl 32 44 4-bromoanilino methyl 28 28 4-chloroanilino methyl 26 26 3-amino-4-chloroanilino methyl 35 34 3-chloro-4-aminoanilino methyl 30 32 2-hydroxybenzylamino methyl 4.2 4.8 3-hydroxybenzylamino methyl 5.8 8. 3 2-methylbenzylamino methyl 20 20 3-methylbenzylamino methyl 30 31 2-chlorobenzylamino methyl 25 25 3-chlorobenzylamino methyl 8. 4 10 furfurylamino methyl allylamino methyl 45 50 Cyclohexylamino methyl 35 30 Cyclopentylamino methyl 30 45 Cyclobutylamino methyl 35 28 Isopentenylamino methyl 45 44 4-chlorobenzylamino methyl 20 18 benzylamino ethyl 14 16 3-chloroanilino ethyl 22 21 anilino ethyl 19 24 3-chloro-5-aminoanilino ethyl 25 28 3-chloro-4-carboxyanilino ethyl 24 29 3-carboxy-4-chloroanilino ethyl 34 40 3-carboxy-4-hydroxyanilino ethyl 4-bromoanilino ethyl 26 28 4-chloroanilino ethyl 27 28 3-amino-4-chloroanilino ethyl 26 28 3-chloro-4-aminoanilino ethyl 4 5. 2 2-hydroxybenzylamino ethyl 5.5 7.2 3-hydroxybenzylamino ethyl 18 17 2-methylbenzylamino ethyl 28 31 3-methylbenzylamino ethyl 25 24 2-chlorobenzylamino ethyl 8.8 9. 4 3-chlorobenzylamino ethyl 18 16 furfurylamino ethyl 42 48 allylamino ethyl 34 32 cyclohexylamino ethyl 29 46 cyclopentylamino ethyl 35 28 cyclobutylamino ethyl 45 44 isopentenylamino ethyl 20 18 4-chlorobenzylamino ethyl 8 5.3 benzylamino isopropyl 1.1 1.2 3-chloroanilino isopropyl 2.0 0.8 anilino isopropyl 4.4 5. 2 3-chloro-5-aminoanilino isopropyl 2.8 2.9 3-chloro-4-carboxyanilino isopropyl 3.2 4.1 3-carboxy-4-chloroanilino isopropyl 1.6 1.7 3-carboxy-4-hydroxyanilino isopropyl 2.2 3.6 4-bromoanilino isopropyl 3.2 3.7 4-chloroanilino isopropyl 3. 1 3. 0 3-amino-4-chloroanilino isopropyl 4. 1 1. 8 3-chloro-4-aminoanilino isopropyl 0.6 0.4 2-hydroxybenzylamino isopropyl 1.7 1.3 3-hydroxybenzylamino isopropyl 2. 1 2.7 4-hydroxybenzylamino isopropyl 2. 2 1. 8 4-methoxybenzylamino isopropyl 2.4 3.1 2-methylbenzylamino isopropyl 1.9 2. 2 3-methylbenzylamino isopropyl 7.4 8.4 2-chlorobenzylamino isopropyl 1. 7 0.7 3-chlorobenzylamino isopropyl 2. 0 1. 4 2-bromobenzylamino isopropyl 5.5 12 furfurylamino isopropyl 4.3 5.3 allylamino isopropyl 13.1 15 cyclohexylamino isopropyl 30 34 cyclopentylamino isopropyl 20 22 isopentenylamino isopropyl 14 15 (2-aminocyclohexyl) amino isopropyl >100 >100 pentylamino isopropyl 3.2 4.2 4-chlorobenzylamino isopropyl 1.7 1. 6 Table 5 shows the results of inhibitory activity of novel compounds against plant in comparison with the data on the prototype compounds (disubstituted purines olomoucine, roscovitine and purvalanol A). Most of the 3,7-disubstituted

pyrazolo [4,3-d] pyrimidine derivatives showed marked inhibitory activity in in vitro plant kinase assays.

EXAMPLE 21: In vitro Cytotoxic Activity of Novel Compounds We have been using the following cell lines: HELA (human cervical carcinoma), MCF7 (human breast adenocarcinoma), NIH 3T3 (mouse fibroblasts), HOS (human osteogenic sarcoma), HL 60 (human promyelocytic leukemia), G 361 (human malignant melanoma), K562 (human chronic myeloblastic leukemia), CEM (human lymphoblastoid leukaemia). Tested drugs were added to the cell cultures in six different concentration and kept at 37 °C and 5% CO2 for three days. All cell lines were grown in DMEM medium (Gibco BRL) supplemented with 10% (v/v) fetal bovine serum and L- glutamine and maintained at 37 °C in a humidified atmosphere with 5% CO2.

104 cells were seeded into each well of 96 well plate, allowed to stabilize for at least 2 h and then tested compounds were added at various concentrations ranging from 200 to 0, 2 uM in triplicates. Three days after drug addition Calcein AM solution (Molecular Probes) was added and let to enter the cells for 1 hour. Fluorescence of viable cells was quantified employing Fluoroskan Ascent (Microsystems). The ICs0 value, the drug concentration lethal to 50% of the tumour cells, was calculated from the obtained dose response curves (Fig. 6).

Cytoxicity of novel compounds was tested on panel of cell lines of different histogenetic and species origin (Tab. 6). Higher activities were found in all tumour cell lines tested. Notably, the higher effectiveness of novel derivatives was also found in cell lines bearing various mutations or deletions in cell cycle associated proteins, e. g. HL-60, BT549, Hela, U20S, MDA- MB231, and Saos2. It indicates that these substances should be equally effective in tumours with various alterations of tumour suppressor genes, namely p53, Rb, etc. Importantly, this observation distinguishes the novel compounds from flavopiridol and related compounds, as their biological activity is dependent on p53 status.

Table 6: Cytotoxicity of Novel Compounds for Different Cancer Cell Lines SUBSTITUENT MCF7 K-562 C7 C3 IC50 (µM) IC50(µM) Olomoucine # # 131, 8 >167 benzylamino methyl 67 89 3-chloroanilino methyl 24 35 2-hydroxybenzylamino methyl 67 55 3-hydroxybenzylamino methyl 119 143 4-hydroxybenzylamino methyl >167 >167 3-hydroxy-4-methoxybenzylamino methyl 58 79 4-methoxybenzylamino methyl 35 53 furfurylamino methyl 142 >167 pentylamino methyl 45 67 cyclobutylamino methyl 89 101 4-aminocyclohexylamino methyl 75 115 2-bromobenzylamino methyl 56 68 benzylamino ethyl 62 81 3-chloroanilino ethyl 19 28 2-hydroxybenzylamino ethyl 63 51 3-hydroxybenzylamino ethyl 111 132 3-hydroxy-4-methoxybenzylamino ethyl 52 72 4-methoxybenzylamino ethyl 31 48 furfurylamino ethyl 135 >167 pentylamino ethyl-62 cyclobutylamino ethyl 82 94 4-aminocyclohexylamino ethyl 71 110 2-bromobenzylamino ethyl 54 60 benzylamino isopropyl 55 72 3-chloroanilino isopropyl 9 12 anilino isopropyl 15 21 3-chloro-5-aminoanilino # isopropyl 29 35 3-chloro-4-carboxyanilino isopropyl 46 69 3-carboxy-4-chloroanilino isopropyl 0. 4 1 3-carboxy-4-hydroxyanilino isopropyl 12 25 4-bromoanilino isopropyl 5 7 4-chloroanilino isopropyl 3 4 3-amino-4-chloroanilino # isopropyl 0.. 2 0.3 3-chloro-4-aminoanilino isopropyl 12 13 2-hydroxybenzylamino isopropyl 63 50 3-hydroxybenzylamino isopropyl 105 132 4-hydroxybenzylamino isopropyl 152 >167 3-hydroxy-4-methoxybenzylamino isopropyl 45 68 4-methoxybenzylamino isopropyl 28 41 2-methylbenzylamino isopropyl 63 75 3-methylbenzylamino isopropyl 76 94 2-chlorobenzylamino isopropyl 15 21 3-chlorobenzylamino isopropyl 24 26 furfurylamino isopropyl 130 > 167 allylamino isopropyl 64 77 cyclohexylamino isopropyl 95 98 pentylamino isopropyl 32 61 cyclobutylamino isopropyl 45 60 isopentenylamino isopropyl >167 >167 2-aminocyclohexylamino isopropyl >167 >167 4-aminocyclohexylamino isopropyl 68 107 2-bromobenzylamino isopropyl 42 57 2-hydroxy-3-methoxybenzylamino isopropyl 0.6 0.8 2-hydroxy-4-methoxybenzylamino isopropyl 0.2 0.5 2-hydroxy-5-methoxybenzylamino isopropyl 0.9 1.2 2-aminobenzylamino isopropyl 0.8 2.1

EXAMPLE 9: Novel Compounds Have Cytotoxic Effects for Plant Cells and Induce their Apoptosis The novel compounds have also been tested in tobacco callus bioassay for cytotoxicity (herbicidal activity) and induction of cell death. The compounds to be tested were dissolved in dimethylsulfoxide (DMSO) and the solution brought up to 10-3 M with distilled water. This tock solution was further diluted in the respective media used for the tobacco bioassay to concentration ranging from 10-8 M to 10-4 M. The final concentration of DMSO in the media did not exceed 0.2%, and therefore did not affect biological activity in the assay system used. Cytokinin-dependent tobacco callus Nicotiana tabacum L. cv. Wisconsins 38 Murashige-Skoog medium, containing per 1 liter: 4, mol nicotinic acid, 2.4 umol pyridoxine hydrochloride, 1.2 jmol thiamine, 26. 6 J. mol glycine, 1.37 umol glutamine, 1.8 (J. mol myoinositol, 30 g of sucrose, 8 g of agar, 5.37 umol a-naphtylacetic acid and 0.5 u. mol 6-benzylaminopurine. Subcultivation was carried out every three weeks. Fourteen days before the bioassay, the callus tissue was transferred to the media without 6-benzylaminopurine. Compounds were

tested with two different concentrations of 6-benzylaminopurine (10-5 M and 10-6 M). Inhibitory growth activity was determined from the increase in fresh callus weight after four weeks of cultivation. Five replicates were prepared for each concentration tested and the entire test was repeated at least twice.

Inhibitory activity was compared with growth response curve of 6- benzylaminopurine in the range from 10-8 M to 10 4 M and IC50 was calculated for each compound for 10-5 M and 10'6 M of 6-benzylaminopurine.

Table 7: Cytotoxicity of Novel Compounds for Tobacco Plant Cells Cultivated in vitro SUBSTITUENT 10'MBAP10'"M BAP C7 C3 IC50 (µM) IC50(µM) OLOMOUCIN >50 >50 benzylamino isopropyl 24 6.5 3-chloroanilino isopropyl 34 8. 2 anilino isopropyl 41 5. 3 2-methylbenzylamino isopropyl 14 4.2 3-methylbenzylamino isopropyl 26 8. 5 2-chlorobenzylamino isopropyl 31 4.6 3-chlorobenzylamino isopropyl 20 1. 7 furfurylamino isopropyl 25 9.4 allylarnino isopropyl 18 3.7 cyclohexylamino isopropyl 46 9.4 cyclopentylamino isopropyl 15. 6 8.4 cyclobutylamino isopropyl 12. 1 4.3 isopentenylamino isopropyl 15. 3 1. 7 4-chlorobenzylamino isopropyl 12.1 4.7 Table 7 shows the results of inhibitory activity of novel compounds on growth of tobacco cells cultivated in vitro in comparison with the data on the prototype compound (trisubstituted purine olomoucine). Most of the 3,7- disubstituted pyrazolo [4,3-d] pyrimidine derivatives showed marked inhibitory activity on in vitro growth. Furthermore, these compounds are able to induce apoptosis in plants cells (are able to kill plant cells) and induce strong antimitotic activities (see Fig. 4 and 5). A dose-dependent inhibition of the cell cycle in Gl/S and G2/M transition points was observed. The appearance of DNA fragmentation

observed by DNA double strand breaks labelling in situ started 3h after drugs addition with highest frequency after 24-48h of treatment, when oligonucleosomal DNA ladder occurred. The high doses of roscovitine, bohemine which induced apoptosis were shown to downregulate in vivo activity of cdk; decrease of cdk protein level was shown by Western blotting and immunofluorescence labelling.

Microtubule reorganization contributing to apoptotic morphology. was observed. The results presented here clearly show that the novel compounds exhibit herbicidal activity