Amberlite IR 120 is a gel type strongly acidic cation exchange resin of the sulphonated polystyrene type (Figure 2.1). It is used for water demineralisation (in H+ form) in co-flow regenerated units. It is an excellent general purpose cation exchange resin that can be used for a wide variety of water demineralization applications. It has excellent physical, chemical and thermal stability and has emerged as an efficient heterogeneous catalyst for various organic reactions like N-formylation of amines, synthesis of various organic compounds like glycosyldihydropyridones, 1-amidoalkyl-2-naphthols, 2-aryl-benzimidazoles, glycosyl enamines and synthesis of nitriles under solvent free microwave irradiation. Figure 2.1: Amberlite IR-120 resin
In this context, an efficient, simple and environmentally friendly method has been developed for the synthesis of substituted imidazoles derivatives through the condensation of Benzil / Benzoin, aryl/alkyl aldehyde and ammonium acetate or amine dissolved in EtOH via multicomponent condensation strategy catalyzed by Amberlite IR 120H+ as solid acid catalyst (Scheme 2.1). The key advantages of this process are high yields, reusability of catalyst, environmental friendliness, easy work-up and purification of products by non- chromatographic methods.…show more content… The best result was achieved by carrying out the reaction with 1:1:2.5 mole ratios of benzaldehyde, benzil and ammonium acetate in presence of 10% (w/w) Amberlite IR 120 catalyst at 800c for 10 min. The higher amount of the catalyst did not improve the results to a great