2,6-Dimethyl-3-ethyl-4-oxo-4H-pyrido(1,2-a)pyrimidine hydrochloride 2,6-Dimethyl-3-ethyl-4H-pyrido(1,2-a)pyrimidin-4-one monohydrochloride 4H-Pyrido(1,2-a)pyrimidin-4-one, 2,6-dimethyl-3-ethyl-, monohydrochloride 70381-39-4 70381-44-1