Compounds of the formula (I) : and pharmaceutically acceptable salts are described, wherein R' is hydrogen or methyl; and R2 and R3 are independently hydrogen, C1-4alkyl, phenyl(C1-4)alkyl or pyridyl(C1-4)alkyl, any of such groups being optionally substituted by one or two hydroxy, C1-4alkoxy or C1-4 alkyl groups; or R2 and R3 together with the carbon atoms to which they are joined form a benzene ring which is optionally substituted by C1-4alkyl.These compounds have inotropic, vasodilator, bronchodilating and platelet aggregation inhibiting properties. Pharmaceutical compositions are described as are methods of use. Intermediates and processes for the preparation of the compounds of the formula (I) are described.
The invention relates to 2-aminopyrimidinone derivatives that have utility as cardiac stimulants. A compound of the invention is 6-[4-(1,4-dihydro-4-oxo-2-pyrimidinylamino)phenyl]-5-methyl-4,5-dihydro-3( 2H)-pyridazinone.