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 pyrazolo3,4-d]pyrimidine, pyrazolo3,4-e]1,4]diazepine, pyrazolo3,4-d]1,2,3]triazine and pyrolo4,3-e]1,2,4]triazolo1,5-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.