Methanesulfonic Acid → HCID 61142891, compound

Participants

Reaction Conditions

Reaction Steps

This compound was isomerized to the fumaryl amide ester by the following procedure. (Z)-N-(3-Carboxy-1-oxo-2-propenyl) -L-alanine methyl ester (67.5 g.) was mixed with 1.28 g. thiourea and 2.18 ml. anhydrous methanesulfonic acid in 675 ml. dry ethyl acetate. The mixture was stirred at reflux for one hour and cooled to 25° C. After addition of 500 ml. water, the organic layer was separated and dried over anhydrous sodium sulphate. The solution was filtered and the solvent distilled under vacuum of 1-2 mm Hg leaving a solid residue that was dried to constant weight affording 50.1 g (74.2% yield) of the (E)N-(3-carboxy-1-oxo-2-propenyl)-L-alanine methyl ester. The NMR in d6 -dimethyl sulfoxide showed the product to be free of the Z-isomer.

Provenance & Evidence