New and rapid access to synthesis of novel polysubstituted imidazoles using antimony trichloride and stannous chloride dihydrate as effective and reusable catalysts

Abstract

In this work, new, efficient and environmentally adapted synthesis of polysubstituted imidazoles in one-pot is repoted. The multicomponent reaction of various aldehydes, benzil, aliphatic and aromatic primary amines and ammonium acetate under solvent-free condition is explained. The highly efficient role of antimony trichloride and stannous chloride dihydrate as catalyst in this synthesis was shown and their effects on the reaction process were studied. By this advantage, several polysubstituted imidazoles as pharmaceutical important molecules can be prepared in high yield and high purity. This method is a very easy and rapid for the synthesis of imidazole derivatives.

Ultrasound-assisted and Efficient Knoevenagel Condensation Reaction Catalyzed by Silica Sodium Carbonate Nanoparticles

“…Over the past few decades, several methods have been proposed and developed by chemists for Knoevenagel condensation reactions. For instance, running the reaction in the presence of Lewis acids or bases, [12,13] ionic liquids, [14] green solvents, [15] microwave assistance, [16] ultrasound irradiation, [17] solid-phase reactions, [18] grinding methods, [19] solvent-free microwave assisted conditions, [20] and using biocatalysts, [15,21] organocatalysts [22] or polyoxometalates [23] could be countered as these methodologies. Furthermore, there are a few reports that have been applied to Knoevenagel condensation under different conditions including continuous flow synthesis, [24] or fluorous biphasic system.…”

One-Pot Synthesis of 2,4,5-Triphenyl Imidazoles from 1,2-Diols as Key Reagents

“…The most important of these are (1) one‐pot cyclocondensation of aldehydes with benzoin or benzil and ammonium acetate, (2) one‐pot cyclocondensation of aldehydes with benzil, aromatic amine, and ammonium acetate, and (3) one‐pot cyclocondensation of aromatic nitriles . This has led to the development of new, improved methodologies involving the use of a number of catalysts such as Yb(OPf) 3 , Cu(NO 3 ) 2 /zeolite, potassium dihydrogen phosphate, ZrOCl 2 .8H 2 O, Zr(acac) 4 , NiCl 2 .6H 2 O, p ‐toluenesulfonic acid (PTSA), TiCl 4 ‐SiO 2 , MCM‐41, ZrCl 4 , sodium bisulfite, polymer‐supported zinc chloride, alum, zinc oxide, trichloroisocyanuric acid, tetrabutyl ammonium bromide, ceric ammonium nitrate, nano copper/cobalt ferrites, microwave, amberlyst, novel polymers, antimony trichloride/stannous chloride dihydrate, SbCl 3 /SiO 2 , sulfamic acid/Fe 3 O 4 , and nano aluminum nitride . Although several methodologies have been documented, most of them have their own drawbacks such as poor yields, the use of toxic catalysts, and tedious work‐up.…”