NEW METHODS OF PREPARATION OF NITRILE OXIDES AND THE CORRESPONDING DISUBSTITUTED FUROXANS BY INTERACTION OF N2O4 WITH SALTS OF SUBSTITUTED DINITROMETHANES

A new method of generation of nitrile oxides through interaction of N2 O4 with salts of substituted dinitromethanes (1) has been worked out. It has been shown by H-1, C-13, N-14 NMR spectroscopy that this reacti on proceeds via dinitronitrosomethyl intermediates (one of these has b een isolated), and that the reaction is feasible only for substituents capable of conjugation with the nitrile oxide fragment. On the basis of cyclodimerization of the obtained nitrile oxides, preparative metho ds of synthesis of symmetrically substituted furoxans have been develo ped.