Premium
Synthetic and antimicrobial studies of N ‐substituted‐pyrazoline‐based new bisheterocycles
Author(s) -
Nisa Shehneela,
Yusuf Mohamad
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.3910
Subject(s) - chemistry , semicarbazide , antimicrobial , hydrazine (antidepressant) , hydrate , pyrazoline , anhydrous , xylene , acetone , chalcone , proton nmr , organic chemistry , reagent , medicinal chemistry , nuclear chemistry , benzene , chromatography
In the present study, the four series of N ‐acetyl/ N ‐carbothioamide/ N ‐carboxamide/ N ‐phenyl‐based new bispyrazolines have been synthesized. These symmetrical bisheterocyclic products were prepared efficiently from the ring‐closure reactions of new bischalcones 2a‐d with appropriate cyclizing agents (hydrazine hydrate, thiosemicarbazide, semicarbazide, and phenyl hydrazine) under the alkaline ethanolic conditions. The compounds 2a‐d were obtained by treating hydroxyl‐substituted chalcone 1 with various dihalogenated reagents (α,α′‐dibromo‐ o/m/p ‐xylene and 4,4′‐bischloromethyl‐diphenyl) in anhydrous K 2 CO 3 /dry acetone/Bu 4 N + I − medium. The structures of all the newly synthesized products have been authenticated with the help of their IR, 1 H‐NMR, 13 C‐NMR, and ESI‐MS spectral data and their purity was corroborated with the help of elemental analysis and thin‐layer chromatography results. The in vitro antimicrobial screening of the newly synthesized intermediates and final bisheterocycles has also been performed by using the serial tube dilution technique against the selected number of microorganisms. The final bisheterocycles revealed better antibacterial and antifungal potencies as compared to their corresponding bischalcones. Among the symmetrical bisheterocyclic products, N ‐acetyl and N ‐carbothioamide‐substituted bispyrazolines were found to exhibit potential antimicrobial properties than the other products.