| abstract |
3-Acyl-acrylic acids of formula (I):- (in which A is aryl or heteroaryl opt. substd. by lower alkyl; R1 and R2 same or different, are H, lower alkyl, opt. substd. aroyl, halogen, NO2, acetylamino, CN, carbamoyl opt. substd. by one or more alkyl, carboalkoxy, OH, alkoxy, alkylthio, or alkylsulphenyl, or one of R1 and R2 may be cycloalkyl or cycloalkenyl opt. substd. by CN or alkyl, allyloxy, dialkylaminoalkyl, heteroaryl opt. hydrated, aryl opt. substd. by lower alkyl, halogen, NO2, acetylamino, CN, carbamoyl which may be substd. by one or more alkyl, carboalkoxy, OH, alkoxy, alkylthio or alkylsulphenyl, and R3 is H or lower alkyl) comprises reacting a ketone of formula (II): with a glyoxylic acid or its deriv. of formula (III): (in which R4 is H or lower alkyl; R5 and R6, same or different, are H, lower alkyl, or together form alkylene) in presence of acid condensation agent at 50 - 200 degrees C. Cpds. (I) are inters. for antiinflammatory and antitussive crotonic acid cpds. |