Synthesis of Novel Pyrido[1,2-a]pyrimidine-3-carboxamide Derivatives and Their Anticancer Activity.

A series of novel pyrido[1,2-a]pyrimidine-3-carboxamide derivatives 6a-n were prepared starting from 2(1H) pyridone 1 via hydrolysis, de-carboxylation, selective O-alkylation followed by rearrangement to give pyridine-2-amine 3. Compound 3 on reaction with ethoxy methylene malonic diethyl ester (EMME) under a conventional method followed by cyclization under micro wave irradiation (MWI) conditions resulted in product 5. Compound 5 on coupling with diverse substituted aliphatic amines formed title compounds 6a-n. All the products 6a-n were screened against four human cancer cell lines and compounds 6h-k and n which showed promising anticancer activity have been identified.