ChemInform Abstract: A Novel Thermal Rearrangement in the Pyrido(1,2-a)pyrimidine Series: Transformation of 3-Acetyl-4-phenylaminopyrido(1,2-a)pyrimidin-2-one into 3-Acetyl-2-phenylaminopyrido(1,2-a)pyrimidin-4-one

3-Acetyl-4-phenylaminopyrido[1,2-a]pyrimidin-2-one has been synthesized from acetoacetic acid N-(pyrid-2-yl)amide and phenylisocyanate and converted on heating into 3-acetyl-2-phenylaminopyrido[1,2-a]pyrimidin-4-one.