131511-64-3 Pyrido(2,3-d)pyrimidine-6-carboxylic acid, 1,4-dihydro-2-((2-(diethylamino)ethyl)thio)-7-methyl-4-oxo-1-phenyl-, ethyl ester, monohydrochloride Pyrido(2,3-d)pyrimidine-6-carboxylic acid, 2-((2-(diethylamino)ethyl)thio)-1,4-dihydro-7-methyl-4-oxo-1-phenyl-, ethyl ester, monohydrochloride