Pyrimidine compounds having activity as a cardiotonic anti-hypertensive cerebrovascular vasodilator and anti-platelet aggregation agent

Claim 1

A pyrimidine compound of the formula: ##STR32## wherein R 1 is hydrogen, di(lower)alkoxyphenyl or pyridyl; R 2 is (a) ═N--R a 2 or (b) ##STR33## or --O--R a 2 in which R a 2 is 2,4,6-tri(lower)alkylphenyl, aminophenyl or acylaminophenyl and R b 2 is lower alkyl, R 3 is hydrogen, lower alkyl or no significance; R 4 is (a) imino optionally substituted with lower alkyl, phenyl or benzyl or (b) lower alkyl, hydrogen, halogen, lower alkylthio, amino optionally substituted with one or two substitutent(s) selected from lower alkyl, phenyl, benzyl and acyl, --NC or hydrazino optionally substituted with one acyl, in which --NC is teteahydropyridin-1-yl or 1-piperazinyl optionally substituted with one acyl, R 5 is hydrogen, lower alkyl, lower alkanoyl optionally substituted with one lower alkylamino or no significance; R 6 is hydrogen, lower alkyl, or di(lower)alkoxyphenyl; the --bond represents single bond or double bond; and the dotted line in the ring A represents one, two or three additional C--C and/or C--N bond(s) in the ring system, provided that R 1 and R 6 are not both hydrogen; and pharmaceutically acceptable salt thereof.