Synthesis, reactions, and spectral characterization of some new biologically active compounds derived from thieno[2,3-c]pyrazole-5-carboxamide

The starting compound 4-amino-3-methyl-1-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide (1), that has been previously synthesized according to the literature procedure, underwent a reaction with the anhydride of phthalic acid either in AcOH or DMF to give isoindolinylpyrazole-5-carboxamide 3 and pyrazolothienopyrimidoisoindoledione 4, respectively. Also, it was subjected to react with diethylmalonate followed by hydrazinolysis by hydrazine hydrate to yield the pyrazolothienopyrimidinyl acetohydrazide 5. The carbohydrazide derivative 5 was used as a key intermediate for the preparation of other new heterocyclic systems containing pyrazolylacetyl pyrazolothienopyrimidines and pyrazolothieno-pyrimidotriazepine compounds 6–11. The structures of these new heterocycles have been characterized by using analytical and spectroscopic analyses (IR, ¹H-NMR, ¹³C-NMR and MS). Some derivatives of the synthesized compounds exhibited remarkable antibacterial and antifungal activities against many bacterial and fungal strains.