Pyrazoles as Building Blocks in Heterocyclic Synthesis: Synthesis of Pyrazolo [3,4-d]pyrimidine, Pyrazolo[3,4-e][1,4]diazepine, Pyrazolo [3,4-d][1,2,3]triazine and Pyrolo [4,3-e][1,2,4]triazolo[1,5-c]pyrimidine Derivatives

Several new pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4-e][1,4]diazepine, pyrazolo[3,4-d][1,2,3]triazine and pyrolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives were prepared by the reaction of the corresponding 5-amino-pyrazole-4-carbonitrile derivative with different organic reagents under different reaction conditions. Using IR, 1H NMR, and mass spectra we have characterized all new compounds