An efficient green protocol for the synthesis of 1,2,4,5-tetrasubstituted imidazoles in the presence of ZSM-11 zeolite as a reusable catalyst

Abstract

We synthesized a series of ZSM-11 zeolite catalysts, investigating the effect of varying the reaction time interval from 18 to 48 h. The ZSM-11 zeolite (48 h) has higher catalytic activity for the synthesis of 1,2,4,5-tetrasubstituted imidazoles.

Preparation of polysubstituted imidazoles using AC-SO3H/[Urea]7[ZnCl2]2as an efficient catalyst system: a novel method, and α-glucosidase inhibitor activity

“…Compared with other studies, the starting materials for synthesis polysubstituted imidazole frames were used as aniline, benzil, ammonium acetate, and benzaldehyde and showed similar yields. 33,69–71 This method improved the yield of the main product while producing pure polysubstituted imidazole frames in a short amount of time. It was also clean and ecologically friendly.…”

Zn(OAc)2•2H2O-catalyzed one-pot synthesis of divergently substituted Imidazoles

“…The product was refined either by recrystallizing in hot ethanol or by column chromatography on silica gel (60-120 Mesh, 20% EtOAc/Petroleum ether mixture) after the organic layer had been concentrated under vacuum. Through the use of FT-IR, 1 H-NMR, 13 C-NMR, and mass spectrum analysis, each product was sufficiently characterized and compared with literature data [20][21][22][23][24] The mixture of aromatic aldehyde (1 mmol), aromatic primary amine (1 mmol), benzil (1 mmol), ammonium acetate (1 mmol), and Zn(OAc)2•2H2O (5 mol %) under solvent-free conditions was taken in a 10 ml round bottom flask, heated to 70 °C, and kept there while being stirred for the appropriate amount of time. TLC was used to monitor the reaction's progress.…”

“…14 In photography, photosensitive imidazole compounds are employed. 15 Keeping in view of the importance of imidazole moiety, various synthetic methodologies are being developed as a continuous process for achieving better atom economy, eco-friendly and cost-effectiveness and several recent reviews [16][17][18][19] and research articles [20][21][22][23][24] have well documented the same. Toxic transition metal catalyst, protic acids, extended reaction durations, high temperatures, low to moderate yields, volatile organic solvents, and the majority of methods of production for tri and tetraarylimidzoles have above disadvantages.…”

Magnetic polyborate nanoparticles as a green and efficient catalyst for one-pot four-component synthesis of highly substituted imidazole derivatives

“…[72][73][74][75] Different homogeneous or heterogeneous catalytic systems have been deployed for the multi-component synthesis of substituted imidazoles including ZSM-11 or HY zeolite, dimethylpyridinium trinitromethanide, 3-picolinic acid, silica sulfuric acid, ZrO 2 -Al 2 O 3, ZrO 2 -b-cyclodextrin, nano-Al-MCM-41, triethylammonium acetate as an ionic liquid, I 2 , Keggintype hetero polyacids, chitosan-coated Fe 3 O 4 nanoparticles, Fe 3 O 4 -PEG-Cu, Boehmite nanoparticles, silica chloride, 2,6pyromellitic diamide-diacid bridged mesoporous organosilica nanospheres, (N 2 H 5 ) 2 SiF 6 and Fe 3 O 4 /SiO 2 decorated trimesic acid-melamine. 6,40,[76][77][78][79][80][81][82] Despite of their merits, there are also some disadvantages associated with these and similar procedures. These disadvantages include the use of hazardous or expensive reagents, low stability or recyclability of the catalysts as well as yields of desired products, pollution generated during the catalyst preparation, long reaction times and difficult work-up steps.…”