Synthetic and antimicrobial studies of N‐substituted‐pyrazoline‐based new bisheterocycles

Abstract

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 K2CO3/dry acetone/Bu4N+I− medium. The structures of all the newly synthesized products have been authenticated with the help of their IR, 1H‐NMR, 13C‐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.

Naphthyl‐Based Chalcone Derivatives: A Multifaceted Player in Medicinal Chemistry

“…Shehneela Nisa and Mohamad Yusuf effectively produced the symmetrical bispyrazoline products 87 a – t (Figure 14) from the ring‐closure processes [136] . The study found that N‐acetyl 87 e – h and N‐carbothioamide 87 i – l ‐substituted bispyrazolines have potential antibacterial properties compared to other symmetrical bis heterocyclic compounds.…”

“…Shehneela Nisa and Mohamad Yusuf effectively produced the symmetrical bispyrazoline products 87 a-t (Figure 14) from the ring-closure processes. [136] The study found that N-acetyl 87 e-h and N-carbothioamide 87 i-l-substituted bispyrazolines have potential antibacterial properties compared to other symmetrical bis heterocyclic compounds. The antimicrobial analyses revealed that most intermediate analogs 87 a-d had moderate effects against the tested bacteria, with a MIC of 16 μg/mL.…”

Pyrazolines as potential anti-Alzheimer's agents: DFT, molecular docking, enzyme inhibition and pharmacokinetic studies

“…Because of their several biological activities, pyrazolines have attracted increasing interest in the field of medicinal chemistry. Their antioxidant, 11 anti-inflammatory, 12 antimicrobial, 13,14 antituberculosis, 13 antibacterial 15,16 and antitumoral [17][18][19][20] properties are due to the presence of a heterocyclic ring and their structural variety. 19,21 Pyrazolines are five-membered heterocyclic compounds containing two nitrogen atoms.…”