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.