| abstract |
Described are compounds of the formula <IMAGE> wherein R is hydrogen, lower alkyl, halo, cyano, hydroxy, amino, lower alkylamino, -CH2NH2, CH2OH or COOR''; R' is hydrogen, lower cycloalkyl or lower alkyl; R'' is lower alkyl or -CH2Ar wherein Ar is phenyl, substituted phenyl, furan or thiophene; R''' is COOR'', <IMAGE> and x is oxygen or nitrogen; or a pharmaceutically acceptable salt thereof and their use in the treatment of impaired ventricular myocardial contractility. The compounds exhibit cardiotonic activity. |