A rapid and simple amine-catalyzed microwave-assisted isomerization of maleamides into fumaramides

An improved, efficient, and simple method for the synthesis of nonsymmetrical diamides of fumaric acid is reported. Starting from commercially available substrates, maleic diamides are formed in two steps, and then isomerized in a focused microwave reactor in acetonitrile as the solvent in the presence of a catalytic amount of piperidine, giving the corresponding fumaramides in high yields and purity.