To obtain a new phenylpropionic acid derivative expressed by a specific formula, having less adverse effects such as a gastrointestinal disturbance, a high safety tolerable to the administration for a long period, and anti- inflammatory, analgesic, antipyretic and anti-allergic activities, and useful as a medicine, etc.
This new phenylpropionic acid derivative is a compound of formula I [R1 is a (substituted) alkyl, alkenyl or aryl; R2 is H; R3 is hydroxyl, and oxy or hydoxylimino together with R2; R4 is H, a (substituted) alkyl, alkenyl or aryl; Ra is H or a carboxylic protecting group; Rb is a lower alkyl; a waved line shows a cis- or trans-isomer or their mixture], e.g. 2-[4-(2-methyl-3-oxo-1- butenyl)phenyl]propionic acid. Further, the compound is obtained through the reaction of e.g. a compound of formula II with R1-X in the presence of a base such as sodium hydride in a solvent such as N,N-dimethylformamide at (-)20-100°C for 30min-48hr.
TANAKA KEIICHI
NITTA JUN
CHAGI HISAAKI
MIYAJIMA MIKAKO
