Process for preparing 3-alkyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,51decane derivative

The present invention relates to a process for preparing a 3-alkyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane derivative.

Synthetic resins having high strength, high durability and good moldability are generally used, for example, in wide industrial fields such as the automobiles and electric/electronics industries and architecture. However, under conditions where they are actually used, they undergo deterioration and discoloration by heat, light, oxygen and nitrogen oxides, and have the defect of a molecular weight being reduced, with the result that their strength is reduced and coloring generated.

In order to enhance durability and weather resistance under conditions where synthetic resins are actually used, it has been carried out to add a photo-stabilizer. Such a photo- stabilizer includes, for example, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione, commercially available e.g. as SANOL LS-440 (RTM)).

3-Alkyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivatives or the like, i.e., a raw material for 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione useful as a photo-stabilizer are industrially prepared by reacting 7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane derivatives or the like with an alkylating agent (for example, dodecyl chloride or the like). The alkylation is carried out in the presence of a base (for example, potassium hydroxide or the like); however, since the reaction becomes a non-uniform system, it is carried out, for example, by performing reaction under reflux for a long period of time (for example, 11 hours) using a mixed solvent of xylene and dimethyl sulfoxide as a solvent.

The alkylation reaction in which the 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivative is reacted with an alkylating agent (for example, dodecyl chloride or the like) solves a problem to be solved as an industrial method as mentioned above, that is, a problem that the reaction time is shortened and trouble of recovery of expensive dimethyl sulfoxide is avoided, and aims at providing a novel preparation process of 3-alkyl-7, 7,9,9- tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivative.

The present inventors intensively studied regarding the preparation process of 3-alkyl- 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivative, and, as a result, they newly found an industrially advantageous preparation process of 3-alkyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane derivative by reacting 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivative or a salt thereof with a base using an alkylating agent in the presence of a catalytic amount of quaternary ammonium salt and a base, to accomplish the present invention.

In more detail, the present invention relates to a process for preparing a 3-alkyl-7,7,9,9- tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivative of the formula (IV)

wherein R ¹ represents hydrogen, d-C ₈ alkyl, oxyl, -OH, d-C^alkoxy, d-C^alkoxy interrupted by oxygen, >C=O, -C(O)O-, -0(O)C- Or -S(O) ₂ -; C _r Ci ₂ alkoxy substituted by a phosphonodiester group; C ₅ -Ci ₂ cycloalkoxy, C ₅ -Ci ₅ bicycloalkoxy, C ₃ -Ci ₂ alkenyl, C ₃ -Ci ₂ alkynyl, C ₇ -C ₉ phenylalkyl unsubstituted or substituted on the phenyl by 1 , 2 or 3 Ci-C ₄ alkyl; Ci-Ci ₂ acyl or Ci-Ci ₂ alkoxycarbonyloxy; and R ² represents a C ₆ -Ci ₈ alkyl group; which comprises reacting a 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivative of the formula (I)

wherein R ¹ has the same meaning as defined above, or a salt thereof with a base; using an alkylating agent of the formula (II)

R ² -X (II) wherein R ² has the same meaning as defined above, and X represents an elimination group; in an inert solvent in the presence of a quaternary ammonium salt of the formula (III)

(R ³ ) ₄ N ⁺ Y ^" (III) wherein R ³ independently represents a radical selected from the group consisting of an alkyl group and an aralkyl group; and Y ^" represents an anion; and a base.

R ¹ represents preferably a hydrogen atom, an oxyl group, a d-C ₆ alkyl group or a C ₂ -C ₇ aliphatic acyl group.

The present process for preparing 3-alkyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane derivatives of the formula (IV) makes it possible to shorten the reaction time and to avoid troubles of recovery of the expensive dimethyl sulfoxide. In addition, the present process can be operated easily.

In the present invention, the "CrC ₈ alkyl group" of R ¹ is a straight or branched alkyl group having preferably from 1 to 6 carbon atoms, and can include for example a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group or a hexyl group, preferably a d-C ₄ alkyl group, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.

In the present invention, the "C ₁ -C ₁₂ alkoxy group" of R ¹ is a straight or branched alkyl group having preferably from 1 to 6 carbon atoms, and can include for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy or dodecyloxy.

In the present invention, "d-Ci ₂ alkoxy interrupted by oxygen, >C=O, -C(O)O-, -0(O)C- or -S(O) ₂ -" of R ¹ covers for example an alkoxy group wherein the alkyl is interrupted by one to three oxygen atoms or the alkyl is interrupted by one >C=O group or by one -C(O)O- or -0(O)C- group or by one -S(O) ₂ - group.

- A -

In the present invention, substituted by a phosphonodiester group" of R ¹ o covers for example an alkoxy group wherein the alkyl is substituted by a diester of — P— OH ,

OH O

„ , Il in particular a group — P — OCH ₃ .

OCH ₃

In the present invention, "C ₅ -Ci ₂ cycloalkoxy" of R ¹ covers for example cyclopentoxy, cyclohexoxy, cycloheptoxy, cyclooctoxy, cyclodecyloxy and cyclododecyloxy. C ₅ - CβCycloalkoxy, in particular cyclopentoxy and cyclohexoxy, is preferred.

In the present invention, "C ₅ -Ci ₅ bicycloalkoxy" of R covers for example

In the present invention, "C ₃ -Ci ₂ alkenyl" of R ¹ covers for example 2-methallyl, butenyl, pentenyl and hexenyl. AIIyI is preferred. The carbon atom in position 1 is preferably saturated.

In the present invention, "C ₃ -Ci ₂ alkynyr of R ¹ covers for example 2-butynyl

In the present invention, "C ₇ -C ₉ phenylalkyl unsubstituted or substituted on the phenyl by 1 , 2 or 3 Ci-C ₄ alkyl" of R ¹ covers for example benzyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl, t-butylbenzyl and 2-phenylethyl. Benzyl is preferred.

In the present invention, "CrC^acyl (e.g. aliphatic, cycloaliphatic or aromatic)" of R ¹ is preferably a straight or branched aliphatic acyl group having 2 to 7 carbon atoms, and can include for example an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a sec-butyryl group, a pentanoyl group or a hexanoyl group, preferably a C ₂ -C ₅ aliphatic acyl group, more preferably an acetyl group or a propionyl group, and still more preferably an acetyl group.

In the present invention, of R ¹ covers for example the group methoxycarbonyloxy.

The "C ₆ -Ci ₈ alkyl group" of R ² is a straight or branched alkyl group having from 6 to 18 carbon atoms, and can include for example a hexyl group, an isopentyl group, a heptyl group, an isohexyl group, an octyl group, an isoheptyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group or an octadecyl group, preferably a C ₈ -Ci ₈ alkyl group, more preferably a Ci ₀ -Ci ₄ alkyl group, and still more preferably a dodecyl group.

An "oxyl group" means "-O-."

The amount of the compound of the formula (II) used is advantageously 0.7 to 1.5 mol based on 1 mol of the compound of the formula (I), and preferably an approximately equimolar amount.

The "elimination group" of X is not particularly limited so long as it affects an alkylation reaction as an elimination group and can include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a CrC ₆ alkanesulfonyloxy group such as a methanesulfonyloxy group, an ethanesulfonyloxy group, a propanesulfonyloxy group, a butanesulfonyloxy group, an isobutanesulfonyloxy group, a pentanesulfonyloxy group and a hexanesulfonyloxy group; or a C ₆ -Ci ₀ arylsulfonyloxy group which may be substituted with 1 to 3 substituents selected from the group consisting of a CrC ₆ alkyl group, a halogen atom and a d-C ₆ alkoxy group (CrC ₆ alkyl-O- group) such as a benzenesulfonyloxy group, a toluenesulfonyloxy group, a chlorobenzenesulfonyloxy group, a methoxybenzenesulfonyloxy group and a naphthalenesulfonyloxy group, preferably a chlorine atom, a bromine atom, an iodine atom, a methanesulfonyloxy group, a benzenesulfonyloxy group or a toluenesulfonyloxy group, more preferably a chlorine atom, a bromine atom or an iodine atom, and still more preferably a chlorine atom.

The "alkyl group" of R ³ is not particularly limited so long as it is usually used for a quaternary ammonium salt and can include a CrCi ₈ alkyl group, preferably a CrCi ₂ alkyl group, more preferably a CrC ₈ alkyl group, still more preferably a CrC ₆ alkyl group, particularly preferably a methyl group, an ethyl group, a propyl group or a butyl group, and most preferably a methyl group, an ethyl group or a butyl group (particularly a butyl group).

The "aralkyl group" of R ³ is not particularly limited so long as it is usually used for a quaternary ammonium salt and can include a CrC ₆ alkyl group substituted with 1 or 2 C ₆ -Ci ₀ aryls which may be substituted with 1 to 3 substituents selected from the group consisting of a CrC ₆ alkyl group, a halogen atom and a d-C ₆ alkoxy group (CrC ₆ alkyl-O- group), preferably a d-C ₄ alkyl group substituted with phenyl, tolyl or naphthyl, more preferably a benzyl group, a phenethyl group, a tolylmethyl group or a tolylethyl group, still more preferably a benzyl group, a phenethyl group or a tolylmethyl group, and most preferably a benzyl group.

The "anion" of Y ^" is not particularly limited so long as it is usually used for the quaternary ammonium salt and can include inorganic anions such as a halogen anion, a nitric acid anion, 1/2 sulfuric acid anion and 1/3 phosphoric acid anion; or organic anions such as a carboxylic acid anion, e.g., an acetic acid anion, a chloroacetic acid anion, a trifluoroacetic acid anion, a propionic acid anion, a benzoic acid anion, a toluic acid anion and a naphthoic acid anion or a sulfonic acid anion, e.g., a methanesulfonic acid anion, an ethanesulfonic acid anion, a benzenesulfonic acid anion and a toluenesulfonic acid anion, preferably an inorganic anion or a carboxylic acid anion, more preferably a chloro anion, a bromo anion, an iodo anion, an acetic acid anion, a chloroacetic acid anion, a trifluoroacetic acid anion or a benzoic acid anion, still more preferably a fluoro anion, a chloro anion, a bromo anion or an iodo anion, and most preferably a fluoro anion or a chloro anion.

The amount of the quaternary ammonium salt of the formula (III) used for the reaction of the present invention is preferably a catalytic amount based on the compound of the formula (I), and when an economical viewpoint is taken into consideration, it is preferably approximately 0.01 to 0.5 mol, more preferably approximately 0.02 to 0.2 mol based on 1 mol of the compound of the formula (I).

The base used for the reaction of the present invention is not particularly limited so long as it can react with an acid H-Y (Y ^" ) (wherein Y ^" is the above-mentioned anion) to produce a salt, and can include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal bicarbonates such as sodium hydrogencarbonate and potassium

hydrogencarbonate; alkali metal hydrides such as sodium hydride and potassium hydride; alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium tert- butoxide; organic metals such as methyl lithium, butyl lithium, methyl magnesium bromide and lithium diisopropylamide; or organic amines such as triethylamine, pyridine, lutidine, 1 ,5- diazabicyclo[4.3.0]-5-nonene, 1 ,4-diazabicyclo[2.2.2]octane and 1 ,8-diazabicyclo[5.4.0]-7- undecene, preferably alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, more preferably alkali metal hydroxides or alkali metal carbonates, still more preferably sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate, and most preferably sodium hydroxide or potassium hydroxide (particularly potassium hydroxide).

Further, as the inorganic bases, anhydrides or hydrates may be used.

The amount of the base used for the reaction of the present invention can be approximately e.g. 0.8 to 1.5 mol based on 1 mol of the compound of the formula (I), preferably an approximately equimolar amount.

Further, the "salt of the decane derivative of the formula (I) and a base" obtained by reacting the raw material decane derivative of the formula (I) with a base can be also subjected to an alkylation reaction in the presence or absence of the base (preferably in the absence of it).

The solvent used for the reaction of the present invention is not particularly limited so long as it does not inhibit the reaction and dissolves the starting material to some extent and can include aliphatic hydrocarbons such as hexane, cyclohexane and heptane; aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; halogenated hydrocarbons such as methylene chloride and chloroform; ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran and dioxane; nitriles such as acetonitrile; amides such as N,N-dimethylformamide, N,N-dimethylacetamide and N-methyl-2-pyrrolidone; sulfoxides such as dimethyl sulfoxide and sulforane; alcohols such as methanol and ethanol; or water; or a mixed solvent of these, preferably aromatic hydrocarbons, amides, sulfoxides or water or a mixed solvent of these, more preferably aromatic hydrocarbons (particularly toluene, xylene or chlorobenzene), amides (particularly N,N-dimethylformamide or N, N- dimethylacetamide), sulfoxides (particularly dimethyl sulfoxide) or water or a mixed solvent of these, still more preferably a mixed solvent of aromatic hydrocarbons with from 1 to 3 kinds

of polar solvents selected from the group consisting of amides, sulfoxides and water (further, a volume ratio of the aromatic hydrocarbons and the polar solvents is preferably approximately 1 :1 to 1 :0.05, more preferably approximately 1 :0.2 to 1 :0.1 ), particularly preferably a mixed solvent of toluene or xylene with 1 to 3 kinds of polar solvents selected from the group consisting of N,N-dimethylformamide, dimethyl sulfoxide and water, and most preferably a mixed solvent of xylene with 1 to 2 kinds of polar solvents selected from the group consisting of dimethyl sulfoxide and water. Further, from the economical viewpoint, it is most preferably a mixed solvent of xylene and water (a volume ratio of xylene and water is approximately 1 :1 to 1 :0.1 ) or a mixed solvent of xylene and dimethyl sulfoxide (a volume ratio of xylene and dimethyl sulfoxide is approximately 1 :1 to 1 :0.1 ).

The amount of solvent used can be e.g. 1 to 10 ml/g based on the compound of the formula (I), and preferably 3 to 6 ml/g.

While the reaction temperature of the reaction of the present invention varies depending on the kinds or the like of the raw material compound, the ammonium salt and the solvent, it is usually O ⁰ C to 18O ⁰ C, and preferably 4O ⁰ C to 14O ⁰ C.

While the time of the reaction of the present invention varies depending on the kinds of the raw material compound, the ammonium salt and the solvent, and the reaction temperature or the like, it is from 30 minutes to 10 hours, and preferably from 1 hour to 5 hours.

The compound of the formula (I) used in the reaction of the present invention can be prepared in analogy to a known process (for example, a process described in Sankyo annual report, vol. 35, pages 1 -37 (1983) or the like).

After the reaction according to the present invention, the obtained desired compound is collected from the reaction mixture according to a conventional method. For example, in cases where the reaction mixture contains the insolubles, the desired compound can be obtained by appropriately filtering the insolubles and distilling off the solvent under reduced pressure or by adding water to the reaction mixture or the residue obtained by distilling off the above solvent under reduced pressure, extracting it with a water-immiscible organic solvent, drying the extract and distilling off the extraction solvent under reduced pressure.

Further, the desired compound can be further purified, if necessary, using a conventional method, for example, a recrystalization method, column chromatography or the like.

In the present invention, the compound of the formula (I) is: (1 a) preferably a compound in which R ¹ is a hydrogen atom, an oxyl group, a methyl group or an acetyl group, and

(1 b) more preferably a compound in which R ¹ is a hydrogen atom or a methyl compound, the compound of the formula (II) is: (2a) preferably a compound in which R ² is a Cs-C-is alkyl group and X is a chlorine atom, a bromine atom, an iodine atom, a methanesulfonyloxy group, a benzenesulfonyloxy group or a toluenesulfonyloxy group,

(2b) more preferably a compound in which R ² is an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group or an octadecyl group and X is a chlorine atom, a bromine atom or an iodine atom,

(2c) still more preferably a compound in which R ² is a decyl group, an undecyl group, a dodecyl group, a tridecyl group or a tetradecyl group and X is a chlorine atom, a bromine atom or an iodine atom, and (2d) most preferably a compound in which R ² is a dodecyl group and X is a chlorine atom or a bromine atom (particularly a chlorine atom), and the compound of the formula (III) is:

(3a) preferably a compound in which R ³ is a group independently selected from the group consisting of a methyl group, an ethyl group, a propyl group, a butyl group and a benzyl group and Y ^" is a chloro anion, a bromo anion, an iodo anion, an acetic acid anion, a chloroacetic acid anion, a trifluoroacetic acid anion or a benzoic acid anion,

(3b) more preferably a compound in which (R ³ ) ₄ N ⁺ is a tetramethyl ammonium cation, a tetraethyl ammonium cation, a tetrapropyl ammonium cation, a tetrabutyl ammonium cation, a trimethyl-ethyl ammonium cation, a trimethyl-butyl ammonium cation or a trimethyl-benzyl ammonium cation and Y ^" is a fluoro anion, a chloro anion, a bromo anion or an iodo anion, (3c) still more preferably a compound in which (R ³ ) ₄ N ⁺ is a tetramethyl ammonium cation, a tetraethyl ammonium cation, a tetrabutyl ammonium cation or a trimethyl-benzyl ammonium cation and Y ^" is a fluoro anion or a chloro anion, and

(3d) most preferably a compound in which (R ³ ^N ⁺ is a tetramethyl ammonium cation or a tetrabutyl ammonium cation (particularly a tetrabutyl ammonium cation) and Y ^" is a fluoro anion or a chloro anion.

In the following, the present invention is specifically explained by way of Examples and Reference examples but the present invention is not limited to these.

Example 1 : Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

20.0 g of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione, 18.4 g of dodecyl chloride, 5.9 g of 85% potassium hydroxide and 1.3 g of tetra-n-butylammonium chloride are added to a mixed solvent of 54 ml of xylene and 40 ml of dimethyl sulfoxide, and the mixture is refluxed with heating for 5 hours.

The reaction mixture is filtered and water is added thereto to separate the solution. Methylene chloride is added to the obtained organic layer and the mixture is accurately made to 250 ml to obtain a specimen for quantitative analysis. The specimen is determined by high performance liquid chromatography (HPLC) using a standard article separately synthesized to determine yield of the title compound and obtain 88.3% yield.

Measurement condition of high performance liquid chromatography (HPLC) Column: inertsil ODS-3 (4.6φ x 250 mm) Mobile phase: acetonitrile/water/triethylamine/acetic acid=800/200/1/1 Detector: UV 230 nm Column temperature: constant temperature around 4O ⁰ C

Example 2: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

The reaction and the post-treatment are carried out in analogy to Example 1 except that 10 ml of dimethyl sulfoxide is used instead of 40 ml of dimethyl sulfoxide to obtain the title compound in 89.9% yield.

Example 3: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

The reaction and the post-treatment are carried out in analogy to Example 2 except that 1.2 g of tetra-n-butylammonium fluoride is used instead of 1.3 g of tetra-n-butylammonium chloride to obtain the title compound in 94.2% yield.

Example 4: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

The reaction and the post-treatment are carried out in analogy to Example 2 except that 3.8 g of 95% sodium hydroxide is used instead of 5.9 g of 85% potassium hydroxide to obtain the title compound in 87.6% yield.

Example 5: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

The reaction and the post-treatment are carried out in analogy to Example 2 except that 3.8 g of 95% sodium hydroxide and 1.2 g of tetra-n-butylammonium fluoride are used instead of 5.9 g of 85% potassium hydroxide and 1.3 g of tetra-n-butylammonium chloride, respectively, to obtain the title compound in 92.3% yield.

Example 6: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

After 3.8 g of 95% sodium hydroxide is added to 30 ml of water, 20.0 g of 7,7,9,9- tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione, 26.6 g of dodecyl iodide, 80 ml of xylene and 2.2 g of tetra-n-butylammonium fluoride are successively added thereto and the mixture is refluxed with heating for 6 hours.

The post-treatment is carried out in analogy to Example 1 to obtain the title compound in 83.1 % yield.

Example 7: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

23.4 g of a potassium salt of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione, 18.4 g of dedecyl chloride and 1.3 g of tetra-n-butylammonium chloride are added to a mixed solvent of 54 ml of xylene and 10 ml of dimethyl sulfoxide, and the mixture is refluxed with heating for 5 hours.

The post-treatment is carried out in analogy to Example 1 to obtain the title compound in 85.2% yield.

Example 8: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione. 23.4 g of a potassium salt of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione, 18.4 g of dodecyl chloride and 1.3 g of tetra-n-butylammonium chloride are added to a mixed solvent of 54 ml of xylene, 10 ml of dimethyl sulfoxide and 1.6 ml of water, and the mixture is refluxed with heating for 5 hours.

The post-treatment is carried out in analogy to Example 1 to obtain the title compound in 98.4% yield.

Example 9: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

The reaction and the post-treatment are carried out in analogy to Example 8 except that 1.2 g of tetra-n-butylammonium fluoride is used instead of 1.3 g of tetra-n-butylammonium chloride to obtain the title compound in 94.0% yield.

Example 10: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

The reaction and the post-treatment are carried out in analogy to Example 8 except that 22.0 g of a sodium salt of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione is used

instead of 23.4 g of the potassium salt of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane- 2,4-dione to obtain the title compound in 84.4% yield.

Example 1 1 : Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4- dione.

After 20.0 g of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione is added to 40 ml of methanol, 6.0 g of 85% potassium hydroxide is added thereto and the mixture is heated to 8O ⁰ C, followed by distilling off 20 ml of the solvent (methanol) under an atmospheric pressure. After 60 ml of xylene is added to the mixture, the mixture is heated to 80 to 14O ⁰ C, followed by distilling off 35 ml of the solvent (mixed solvent of methanol and xylene) under an atmospheric pressure to obtain a suspension of the potassium salt of 7,7,9, 9-tetramethyl- 1 ,3,8-triazaspiro[4,5]decane-2,4-dione (about 45 ml).

After the suspension is cooled to room temperature, 9 ml of xylene, 10 ml of dimethyl sulfoxide, 18.4 g of dodecyl chloride, 1.3 g of tetra-n-butylammonium chloride and 1.6 ml of water are added thereto and the mixture is refluxed with heating. After the mixture is cooled to approximately 7O ⁰ C and washed with 40 ml of hot water of approximately 7O ⁰ C four times, the insolubles are filtered.

The post-treatment is carried out in analogy to Example 1 to obtain the title compound in 95.0% yield.

Further, after completion of quantitative analysis, the filtrate is concentrated to dryness under reduced pressure and 10 ml of hydrous methanol (76%) is added thereto. The mixture is heated and dissolved and gradually cooled and crystallized to obtain 31.4 g (yield: 90%) of the title compound.

Melting point: 1 10.0 to 112.1 ⁰ C

Example 12: Preparation of 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

After a xylene mixture (yield: 95%) containing 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione obtained in analogy to Example 1 1 is subjected to azeotropy and dehydrated, 16 ml of acetic anhydride are added thereto. The mixture is heated to 122 ⁰ C to 125 ⁰ C under reduced pressure (-40 mmHg) until a distillate is not distilled. Subsequently, 8 ml of acetic anhydride is added to the mixture and the mixture is heated to 122 ⁰ C to 125 ⁰ C until the distillate is not distilled. Further, the operation is repeated twice until acetic acid is not recognized in the distillate.

After the resulting mixture is cooled to room temperature, 175 ml of hydrous methanol (76%) is added thereto and subsequently 1.7 g of activated carbon and 0.5 g of radio lite are added thereto. The mixture is filtered under reflux with heating. The filtrate is cooled to 5 ⁰ C or lower and the precipitated crystals are filtered to obtain 28.8 g (yield: 79%) of the title compound.

Melting point: 76.5 ⁰ C to 77.8 ⁰ C

Reference example A: Preparation of a potassium salt of 7,7,9, 9-tetramethyl-1 , 3,8- triazaspiro[4,5]decane-2,4-dione. A solution obtained by dissolving 36.0 g of 85% potassium hydroxide in 240 ml of methanol is added to 120.0 g of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione, and the mixture is refluxed for 20 minutes. After the mixture is cooled, it is filtered. After the filtrate is concentrated under reduced pressure, 240 ml of xylene is added thereto and the mixture is concentrated again under reduced pressure, concentrated to dryness and dried to obtain 147.6 g (content: 94.6%) of the title compound.

Reference example B: Preparation of a sodium salt of 7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

A solution obtained by dissolving 9.5 g of 95% sodium hydroxide in 100 ml of methanol is added to 50.0 g of 7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4,5]decane-2,4-dione, and the mixture is refluxed for 30 minutes. After the mixture is cooled, it is post-treated similarly to Reference example A to obtain 57.2 g of the title compound.

Comparative example 1 : Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

The reaction and the post-treatment are carried out in analogy to Example 1 except that 1.3 g of tetra-n-butylammonium chloride is not added to obtain the title compound in 75% yield.

Comparative example 2: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

The reaction and the post-treatment are carried out in analogy to Example 2 except that 1.3 g of tetra-n-butylammonium chloride is not added to obtain the title compound in 20.4% yield.

Comparative example 3: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione. The reaction and the post-treatment are carried out in analogy to Example 4 except that 1.3 g of tetra-n-butylammonium chloride is not added to obtain the title compound in 3.0% yield.

Comparative example 4: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

The reaction and the post-treatment are carried out in analogy to Example 6 except that 2.2 g of tetra-n-butylammonium fluoride is not added to obtain the title compound in 6.0% yield.

Comparative example 5: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

The reaction and the post-treatment are carried out in analogy to Example 7 except that 1.3 g of tetra-n-butylammonium chloride is not added to obtain the title compound in 24.0% yield.

Comparative example 6: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione.

The reaction and the post-treatment are carried out in analogy to Example 8 except that 1.3 g of tetra-n-butylammonium chloride is not added to obtain the title compound in 46.3% yield.

Comparative example 7: Preparation of 3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8- triazaspiro[4,5]decane-2,4-dione. The reaction and the post-treatment are carried out in analogy to Example 10 except that 1.3 g of tetra-n-butylammonium chloride is not added to obtain the title compound in 4.9% yield.