Synthesis of 2-[(Z)-1-hydropolyfluoro-1-alkenyl]-4H-3,1-benzoxazin-4-ones

N,N′-dicyclohexylcarbodiimide induced condensation of 2,2-dihydropolyfluoroalkanoic acid and anthranilic acid or its derivatives followed by a dehydrating ring-closure reaction in the presence of Ac2O gave 2-[(Z)-1-hydropolyfluoro-1-alkenyl]-4H-3,1-benzoxazin-4-ones in good to excellent yields.