Synthesis of 4-fluoroalkyl-2H-pyrido [1, 2-a] pyrimidin-2-ones from 2, 2-dihydropolyfluoroalkanoic acids^†

In the presence of N, N′-dicyclohexylcarbodiimide, 2-aminopyridine and its derivatives (2) condensed with 2, 2-di-hydropolyfluoroalkanoic adds (1) to give the corresponding amides. Subsequent intramolecular Micheal addition-elimination reactions of the fluorine-containing amides under basic conditions gave 4-fluoroalkyl-2H-pyrido[1,2-a]pyrimidin-2-ones (3) in good yields.