AROMATIC DERIVATIVES OF BUTYRIC ACID, PROCESS FOR THEIR PREPARATION AND THEIR COSMETIC AND PHARMACEUTICAL USE

摘要

These derivatives correspond to the following formula: …… in which:… R1, R2, R3 and R4 denote, independently of each other, H or an alkyl radical, at least two of the radicals R1 to R4 being other H,… A denotes a methylene or dimethylene radical and, when A denotes a dimethylene radical, R1 and R3 may together form a methylene or dimethylene radical,… R5 and R6 denote H, a halogen, an alkyl radical, an alkoxy radical or OH,… R' denotes H, OH, an alkoxy radical or an acyloxy radical,… R" denotes H or an alkoxy radical,… or R' and R", taken together, form an oxo or hydroxyimino radical,… R8 denotes H or an alkyl radical… and R7 denotes -OR9 or …… … R9 denoting H, an alkyl radical, a monohydroxyalkyl, polyhydroxyalkyl, aryl or aralkyl radical, optionally substituted, a sugar residue or a carboxyalkyl or alkoxycarbonylalkyl radical,… r' and r" denoting H, an alkyl radical, a monohydroxyalkyl radical optionally interrupted by a hetero atom, a polyhydroxyalkyl radical, an aryl or benzyl radical, optionally substituted, a residue of amino acid or amino sugar or, taken together form a heterocyclic ring, optionally substituted by a C1-C3 hydroxyalkyl radical, and the salts of the said compounds of formula (I) and their optical isomers and the tautomeric forms of the compounds of formula (I).