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Microwave‐assisted synthesis and biological evaluation of pyrazole‐4‐carbonitriles as antimicrobial agents
Author(s) -
Sood Sumit,
Kumari Poonam,
Yadav Ajar Nath,
Kumar Anil,
Singh Karan
Publication year - 2020
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.4003
Subject(s) - chemistry , pyrazole , antimicrobial , reagent , bacillus cereus , yield (engineering) , organic chemistry , dimethylformamide , combinatorial chemistry , candida albicans , hydroxylamine hydrochloride , bacteria , microbiology and biotechnology , genetics , materials science , metallurgy , biology , solvent
An efficient microwave‐assisted method of synthesis of pyrazole‐4‐carbonitriles has been developed. Condensation of pyrazole‐4‐carbaldehydes with hydroxylamine hydrochloride followed by reaction of the resulting oximes with the Vilsmeier‐Haack reagent pre‐formed from phthaloyl dichloride and dimethylformamide under microwave irradiation afforded the corresponding pyrazole‐4‐carbonitriles in 73% to 91% yield. The operational simplicity, avoidance of toxic reagents such as POCl 3 , shorter reaction time, higher yield compared to the classical version, easy work up, and the use of the by‐product in the regeneration of phthaloyl dichloride are the advantages of this methodology. All the target compounds were tested for antimicrobial activity against Gram‐positive bacteria Bacillus cereus and Staphylococcus aureus ; Gram‐negative bacteria Escherichia coli and Yersinia enterocolitica , and the fungal species Candida albicans .