New Method for Synthesis of Multi‐substituted Imidazoles

Abstract

in Wiley Online Library (wileyonlinelibrary.com).Here, we reported two methods for the synthesis of multi-substituted imidazoles, firstly via fourcomponent cyclocondensation reaction of benzil, aliphatic amines (allylamine or pentylamine), and aromatic aldehyde and ammonium acetate. Using an ionic liquid catalyst namely, diethyl ammonium hydrogen sulfate, and under solvent-free conditions. Secondly, via the alkylation of synthesized NH imidazoles with alkyl halide (allyl bromide and pentyl bromide) gave 8a-c in high yield (average 90%), the products can be purified by a non-chromatographic method, and these newly synthesized compounds have been characterized by spectral data: FTIR, IR, 1 H, 13 C nuclear magnetic resonance, the elemental analysis, and the X-ray structure.

Design, Synthesis, and Antibacterial Screening of Some Novel Heteroaryl-Based Ciprofloxacin Derivatives as DNA Gyrase and Topoisomerase IV Inhibitors

“…Continuing our quest to find a compound with improved antimicrobial properties [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], the current study describes the synthesis and structure elucidation of Fluoroquinolone(ciprofloxacin)-based hybrids containing various heterocycle derivatives, as well as antimicrobial activity evaluation using various strains of Gram-positive ( S. aureus and B. subtilis ), Gram-negative ( E. coli and P. aeruginosa ), and fungi ( A. flavus and C. albicans ). In addition, the inhibitory activity of the most active compounds against E. coli DNA gyrase and topoisomerase IV has been identified as a potential molecular target.…”

Piperidinium Hydrogen Sulfate (PHS) as an Efficient Ionic Liquid Catalyst for the Synthesis of Imidazole Derivative under Solvent‐Free Condition

“…Then concentrated sulfuric acid (98%) (39.23 g, 0.40 mol) was added dropwise slowly. The reaction mixture was then stirred at 100°C for 20 h, washed with diethyl ether three times to remove nonionic residues, and dried in vacuum on a rotary evaporator to yield PHS as a clear brownish viscous liquid with yield of 95% .…”

Anticancer Activities of Tetrasubstituted Imidazole‐Pyrimidine‐Sulfonamide Hybrids as Inhibitors of EGFR Mutants

“…[41] The ionic liquid catalysis was advantageous due to much shorter reaction times, excellent yield, ease of stabilization, products can be purified by a non-chromatographic technique, and the catalyst is reusable. [40,41] Motivated by the benefit of this method, we adopted it for the synthesis of our targeted imidazoles. As such, one-pot four-component reactions were conducted between benzyl, ammonium acetate, different benzaldehyde derivatives and pyrimidine sulfonamide in ionic liquid (diethylammonium hydrogen sulfate) and triethylamine.…”

“…[34] Interestingly, further methods that utilize fewer than four components have also been reported, such as the photochemical one-pot threecomponent synthesis (from aldehydes, α-aminonitriles, and isoxazoles) of tetrasubstituted imidazoles, [35,36] from amidines and chalcones via FeCl 3 /I 2 -catalyzed aerobic oxidative coupling, [37] sequential reaction of allenyl sulfonamides and amines, [38] from imines, acid chlorides, and N-nosyl imines or ChemMedChem tethered nitriles and mediated by the phosphonitePPh(catechyl) [39] alkylation of synthesized NH imidazoles with alkyl halide. [40] Recently an interesting, eco-friendly, and solvent-free method for the synthesis of tetrasubstituted imidazoles was reported using ionic liquid catalysts diethyl ammonium hydrogen sulfate [40] and piperidinium hydrogen sulfate. [41] The ionic liquid catalysis was advantageous due to much shorter reaction times, excellent yield, ease of stabilization, products can be purified by a non-chromatographic technique, and the catalyst is reusable.…”