ETHYL 2-NITROACETOACETATE AS A NEW SYNTHETIC EQUIVALENT OF ETHOXYCARBONYLNITRILE OXIDE

It was shown that ethyl 2-nitroacetoacetate is a synthetic precursor o f ethoxycarbonylnitrile oxide as well as of isoxazole- and isoxazoline -3-carboxylic acids and their esters. The elimination of acetic acid f rom ethyl 2-nitroacetoacetate occurs in a mixture of acetic acid and a cetic anhydride in the presence of strong mineral acids, e.g., H2SO4, at room temperature and gives isoxazolines in yields of up to 85-91 %.