Ethyl 5-oxo-3-(4-toluidino)-2,5-dihydro-4-isoxazolecarboxylate was prepared from the reaction of diethyl 2-(4-toluidinocarbothioyl)malonate with hydroxylamine. Its reaction with 2- chlorobenzoxazole gave the corresponding N-substituted isoxazolone. The structure of the final product 4 was confirmed by IR, 1H and 13C NMR spectroscopy and mass spectrometry, and by X-ray single crystal structure determination.