Heterocyclic o-Aminonitriles: Preparation of Pyrazolo34-d-pyrimidines with Modification of the Substituents at the 1-Position

摘要

Novel 1-[6-(p-tolyl) pyridazin-3-yl]pyrazole-o-aminonitriles (>3a-c) were formed using 3-hydrazino-6-(p-tolyl)pyridazine (>2) and ketene S,S-acetals (>1a), S,N-acetals (>1b) or tetracyanoethylene (>1c). The pyrazole-o-aminonitriles (>3a-c) were in turn used as precursors for the preparation of previously unreported 1-[6-(p-tolyl)-pyridazin-3-yl]pyrazolo[3,4-d]pyrimidines (>8, 9, 13-20) and 7-[6-( p-tolyl) pyridazin-3-yl]2-arylpyrazolo[3,4-d]1,2,4-triazolo[5,1-f]pyrimidines (>10-12) which are expected to possess considerable chemical and pharmacological activities.