| abstract |
The compounds of formula I: <IMAGE> (I) wherein R1 and R2 are hydrogen, alkyl or cyclic or bicyclic alkyl; R3 is formyl, alkanoyl, alkenoyl, alkylsulfonyl, aroyl, arylalkenoyl, arylsulfonyl arylalkanoyl or arylalkylsulfonyl; A is a substituted phenyl group of the following formula: <IMAGE> wherein R5 is cyano and R6 is alkyl, chloro, bromo, fluoro or iodo and pharmaceutically acceptable salts thereof, are smooth muscle relaxants. |