Utility of Hydrazidoyl Chlorides : Synthesis of New Pyrazoles, Pyrazolo[ 3,4-d]pyridazines, Pyrazolo[4,5-b]pyridines and Pyrazolo[ 4,5-d]pyrimidine Derivatives

Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt Chemistry Department, Faculty of Science. Suez-Canal University, Ismalia, Egypt Manuscript received 28 October 1991 revised 26 May 1992, accepted 3 June 1992 Hydrazidoyl chlorides (1) were reacted with a variety of active methylene compounds and arylidemnialononitriles .1 medium, to produce polyfunctionally substituted pyrazole derivatives (2-6 and 10). The pyrazoles (2, 3, 6 and 10) were converted into the corresponding pyrazolo[3, 4-d]pyridazine derivatives (7 - 9 and 14), respectively. The aminopyraiole derivative (10) underwent dipolar cycloaddition with acetylisothiocyanate, acrylonitrile and arylidenemalononitrile to produce pyrazolo[4, 5-d]pyrimidine (15) and pyrazolo[4, 5-b]pyridines (16, 17) respectively. Their structures were established on the basis of elemental analyses and spectral data