NITROPYRAZOLES .4. N-AMINATION UNDER CONTROL OF THE PH OF THE MEDIUM

A preparative method of N-amination of pyrazoles bearing nitro groups and other electron withdrawing substituents in the pyrazole ring with hydroxylamine-O-sulfonic acid involving control of the pH of the mediu m has been elaborated. A series of previously unknown pyrazoles has be en prepared. Basicities (pK(BH+)) of 1-aminopyrazole and 1-amino-4-nit ropyrazole have been measured and differences between the basicities o f the C- and N-amino groups for the pyrazole series have been revealed .