An Improved Strategy for the Synthesis of Ethylene Glycol by Oxamate-Mediated Catalytic Hydrogenation

Abstract

The present study reports an improved approach for the preparation of ethylene glycol (EG) by using carbon monoxide as C1 chemical by a two-step oxidative carbonylation and hydrogenation sequence. In the first step, oxamates are synthesized through oxidative cross double carbonylation of piperidine and ethanol by using Pd/C catalyst under phosphine ligand-free conditions and subsequently hydrogenated by Milstein's catalyst (carbonylhydrido[6-(di-t-butylphosphinomethylene)-2-(N,N-diethylaminomethyl)-1,6-dihydropyridine]ruthenium(II)). The presented stepwise oxamate-mediated coupling provides the basis for a new strategy for the synthesis of EG by selective upgrading of C1 chemicals.

Keywords: carbonylation; ethylene glycol; hydrogenation; oxamates; ruthenium.