NITROPYRAZOLES .1. SYNTHESIS, TRANSFORMATIONS, AND PHYSICOCHEMICAL PROPERTIES OF NITRO-DERIVATIVES OF 1H,4H-PYRAZOLO[4,3-C]PYRAZOLE

A method of synthesizing nitro derivatives of 1H,4H-pyrazolo[4,3-c]pyr azole is developed, and some of its transformations are studied. 3-Met hyl-6-nitro-, 3-carboxy(methoxy-carbonyl, carbamoyl)-6-nitro-, 3-amino -6-nitro-, 3-nitro-, 3,6-dinitro-, 1,4-diacetonyl-3,6-dinitro-, and 1H ,4H-3-aminopyrazolo[4,3-c]pyrazoles were obtained from 1H,4H-3-methylp yrazolo[4,3-c]pyrazole. Unsubstituted 1H,4H-pyrazolo[4,3-c]pyrazole, t he first member of this series, was obtained for the first time. The c ompounds prepared were characterized by H-1, C-13, N-14, and N-15 NMR spectroscopy. NH-Acidity and basicity of the series of pyrazolo[4,3-c] pyrazoles synthesized is studied and the effect of the fused pyrazole ring on these properties is examined.