2,6,8-Trimethyl-3-ethyl-4-oxo-4H-pyrido(1,2-a)pyrimidine hydrochloride 3-Ethyl-2,6,8-trimethyl-4H-pyrido(1,2-a)pyrimidin-4-one monohydrochloride 4H-Pyrido(1,2-a)pyrimidin-4-one, 3-ethyl-2,6,8-trimethyl-, monohydrochloride 70381-67-8