Deep eutectic solvent choline chloride·2CrCl3·6H2O: an efficient catalyst for esterification of formic and acetic acid at room temperature

Abstract

A highly efficient and selective method for esterification of formic and acetic acid with alcohols has been achieved at room temperature, with the choline chloride (ChCl)/chromium(III) chloride hexahydrate (CrCl₃·6H₂O) deep eutectic solvent as a catalyst. High yields and good selectivities of organic esters are obtained using DES [ChCl][CrCl₃·6H₂O]₂ with the molar ratio 5 : 1 (carboxylic acids : alcohols) at room temperature in 24 h. The ease of recovery and reusability of DES with high catalytic activity makes this method efficient and practical.