Highly selective synthesis under benign reaction conditions of furfural dialkyl acetal using SnCl2 as a recyclable catalyst
A new and mild route of furfural acetalization with various alkyl alcohols catalyzed by the cheap and simple SnCl2·has been developed. This process consists in the conversion of furfural to alkyl acetals under benign and mild reaction conditions (i.e., room temperature, without solvent, recyclable catalyst), achieving a very good selectivity (97–100%) and the almost complete conversion of the furfural. Various tin(II) salts were used as catalysts to the upgrading of furfural to alkyl acetal in an alcoholic solution at room temperature. SnCl2 was the most active and selective catalyst toward furfural diethyl acetal. Tin(II) chloride is a commercially available and water-tolerant Lewis acid and demonstrated to be an efficient and recyclable catalyst for the synthesis of furfural alkyl acetal. Effect of main variables of reaction such as catalyst load, temperature, reaction time and alcohol nature were assessed. SnCl2 was easily recovered and reused without loss of activity and selectivity.