摘要 |
<p>Aromatic heterocyclic derivatives have the formula <IMAGE> wherein R1 represents <IMAGE> wherein R3 represents hydrogen, -OR4 wherein R4 represents hydrogen, alkyl having 1-20 carbon atoms or mono- or polyhydroxyalkyl or R3 represents <IMAGE> wherein r' and r'' represent hydrogen, lower alkyl or together form a heterocycle, R2 represents hydrogen or -CH3 and Ar represents <IMAGE> (A) <IMAGE> (B) wherein Z is O or S, <IMAGE> (C) wherein R5 is lower alkyl or <IMAGE> (D) wherein R6 is hydrogen or alkyl having 1-10 carbon atoms and R7 represents alkyl having 4-12 carbon atoms or cycloalkyl, Y is CH or a nitrogen atom and X represents oxygen, sulfur or -N-R8 when R8 represents hydrogen, lower alkyl or lower alkoxycarbonyl, with the proviso that (i) when Y is CH and X is oxygen or sulfur Ar is other than C and (ii) when Y is nitrogen and X is oxygen, Ar is other than (C) or (D) in which R6 is alkyl having 1-4 carbon atoms and R7 is branched alkyl having 4-12 atoms useful in veterinary or human therapy and in cosmetic formulations.</p> |