Design, synthesis and characterization of fluoro substituted novel pyrazolylpyrazolines scaffold and their pharmacological screening

• Microwave promoted synthesis of fluorinated pyrazolylpyrazolines is illustrated.
• Biological screening of the title compounds has been performed.
• SAR study of fluorinated pyrazolylpyrazolines has been discussed.
• Compounds 7a, 7b, 7g, 7h, 7j and 7k exhibited superior antimalarial potency.
• Compound 7h exhibited interesting dual antimalarial and antituberculosis profile.

A novel series of fluoro substituted pyrazolylpyrazolines 7a–l was synthesized in good to excellent yield (77–88%) from pyrazole chalcones 5a–d and substituted phenyl hydrazine hydrochlorides 6a–c under microwave irradiation. The newly synthesized compounds were screened for their preliminary in vitro antibacterial activity against a panel of pathogenic stains of bacteria and fungi, antituberculosis activity against Mycobacterium tuberculosis H37Rv and antimalarial activity against Plasmodium falciparum. Compounds 7a, 7b, 7g, 7h, 7j and 7k displayed excellent activity against P. falciparum stain as compared to quinine IC50 0.268. Good antitubercular activity was exhibited by compounds 7a, 7e, 7h and 7k. Some of them also exhibited superior antibacterial activity as compared to the first line drugs.

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