2-Butenedioic acid (E)-, monoethyl ester (9CI) 2459-05-4 55141-86-1 62008-21-3 62008-22-4 76260-93-0 EINECS 219-544-7 Ethyl fumarate Ethyl hydrogen fumarate Fumaric acid, ethyl ester Fumaric acid, monoethyl ester Monoethyl fumarate Monoethyl trans-2-butenedioate NSC 524101