Isoxazole derivatives were characterized by broad spectrum of biological activities, but the condensed heterocyclic compounds containing isoxazole were scarcely reported. In this paper, we studied the 1,3-dipolar cycloaddition of p-methoxybenzohydroxamoyl chloride with ethyl sodioacetoacetate to obtain a key intermediate 2. Through compound 2, fifteen novel S-triazolo-1,3,4-thiadiazines(5a-5e), imidazolo-1,3,4-thiadiazoles(9a-9e) and imidazolo-1,3,4-oxadiazoles(10a-10e) containing isoxazole, which have potentially useful biological activities, were synthesized. The structures of the products were confirmed by elemental analyses and spectral analysis. And the characteristic data of IR, 1H NMR and MS were explained reasonably.
