Facile and Efficient Synthesis of Tetrahydrobenzimidazo [2,1-b]Quinazolin-1(2H)-One Derivatives Using Brönsted Acidic Ionic Liquid Immobilized on Nanoporous Na⁺-Montmorillonite

Abstract

In this work, an efficient and green procedure have been described for the synthesis of tetrahydrobenzimidazo[2,1-b]quinazolin-1(2H)-one derivatives using nanoporous sodium montmorillonite clay (Na+-MMT) modified with 1-methyl-3-(trimethoxysilylpropyl)-imidazolium hydrogen sulfate (Na+-MMT-[pmim]HSO4). The procedure gave the products in excellent yields in very short reaction times under solvent-free condition. Also this catalyst can be reused for six times without considerable loss of its catalytic activity.

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

“…The development of new catalytic systems and determination of their efficiency in MCR was the goal of a large number of studies related to the development of MCR methodology. [81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96] The use of new catalysts and their systems allows: simplifying the procedure for obtaining the target product, increasing the selectivity of the process,…”

“…3). [88][89][90][91][92] Among the advantages of the considered catalysts are their cheapness, ease of preparation, and high stability. In addition, the research emphasizes the possibility of reuse of catalysts without losing their activity.…”

Synthesis and characterization of silica‐coated Fe3O4 nanoparticle@silylpropyl triethylammonium polyoxometalate as an organic–inorganic hybrid heterogeneous catalyst for the one‐pot synthesis of tetrahydrobenzimidazo[2,1‐b]quinazolin‐1(2H)‐ones

“…[Bmim]Br 50 [44] 4 F e 3 O 4 @SiO 2 -ZrCl 2 -MNPs 42 [45] 5 Molybdate sulfuric acid 35 [46] 6 F e 3 O 4 @IM 44 [47] 7 DABCO-based ionic liquid 45 [49] 8 Sc(OTf) 3 29 [48] 9 N a + -MMT-[pmim]HSO 4 39 [50] 10 AcOH 31 [51] 11 TBABr 51 in solvents such as toluene, xylene, and chloroform (Table 2, Entries 1-10). The reaction was efficiently accomplished in an ethanol solvent.…”

“…This synthetic method can be performed under solvent‐free conditions, [ 39 ] MW iradiation [ 40 ] and ultrasound irradiation. [ 41 ] Furthermore, various catalysts such as H 6 P 2 W 18 O 62 ·18H 2 O, [ 42 ] SBA‐Pr‐SO 3 H, [ 43 ] [Bmim]Br, [ 44 ] Fe 3 O 4 @SiO 2 –ZrCl 2 ‐MNPs, [ 45 ] molybdate sulfuric acid, [ 46 ] Fe 3 O 4 @IM, [ 47 ] Sc(OTf) 3 , [ 48 ] DABCO‐based ionic liquid, [ 49 ] Na + ‐MMT‐[pmim]HSO 4 , [ 50 ] AcOH, [ 51 ] and TBABr [ 52 ] have been utilized in this process. However, these synthetic protocols suffer from one or more disadvantages such as harsh reaction conditions, prolonged reaction times, low yields, or use of toxic solvents such as methanol, acetic acid, tetrahydrofuran, and dimethylformamide.…”

Facile synthesis of triazolo/benzazolo[2,1-b]quinazolinone derivatives catalyzed by a new deep eutectic mixture based on glucose, pregabalin and urea

“…A common way for the preparation of these important target molecules is the multi-component reaction of aldehydes with 3-amino-1,2,4-triazole or 2-aminobenzimidazole, and a β-diketone in the presence of a variety of catalysts. 31–36…”