How is 3-(2-Chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (CAS: 93076-03-0) typically synthesized?

3-(2-Chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (CAS: 93076-03-0) is synthesized via a multi-step process involving the reaction of 2-chloroethylamine with 2-methyl-4,5,6,7-tetrahydro-1H-pyrimidine-4-one. The synthesis typically uses anhydrous conditions and requires careful control of pH and temperature to achieve high yields. The reaction is catalyzed by an appropriate base, and the final product is isolated by crystallization.