Heterocyclic syntheses with malonyl chloride. Part IX. 2-Substituted 4-chloro-6-pyrimidones from certain nitriles
Abstract
Chloroacetonitrile with malonyl chloride yielded 2,3-dichloro-4,6-dihydroxypyridine together with an unexpected product, 4-chloro-2-chloromethyl-6-pyrimidone. Further examples of this new synthesis of 2-substituted 4-chloro-6-pyrimidones were obtained with fluoro- and bromo-acetonitrile, α-bromopropionitrile, and acetonitrile. Propio- and butyro-nitrile each gave a mixture of pyridine and pyrimidine product, whilst various other nitriles gave only the pyridine products. The expected fully substituted pyrimidone was obtained from fluoroacetonitrile and chloromalonyl chloride, and from dibromoacetonitrile with bromomalonyl chloride. Some novel halogen-transfer reactions were encountered in other cases.