1,3-Dipolar Cycloaddition Reaction of Nitrile Oxides to Isatin Imines

A simple and efficient onepot route for the synthesis of novel spiro [indolin– oxadiazol] derivativesby 1,3dipolar cycloaddition reaction of nitrile oxides and isatin imine under classical or microwave irradiation conditions is described.4amino5methyl2,4dihydro3H1,2,4triazole3thione was synthesized by cyclization of thiocarbohydrazide and acetic acid. 3((3methyl5thioxo1,5dihydro4H1,2,4triazol4yl)imino)indolin2one was prepared by condensation of primary amine of 4amino5methyl2,4dihydro3H1,2,4triazole3thione with isatin through a single step and 4(3methyl5thioxo1H1,2,4triazol4(5H)yl) 3(substituted phenyl)4hydro spiro[indolin3,5[1,2,4]oxadiazol]2one were afforded by the reaction of corresponding Schiff base with hydroximinoyl chloride and their derivatives under basic conditions at room temperature. The products were obtained in good yields. Elemental analysis, IR, 1H NMR, 13C NMR, and Mass spectral data confirmed the structure of newly synthesized compounds.