2-Butenedioic acid, 2-[5-iodo-2,4-dioxo-3-(2-propynyl)-1H,3H-pyrimidinyl]-,diethyl ester, (2E)- Fumaric acid, 2-[5-iodo-2,4-dioxo-3-(2-propynyl)-1H,3H-pyrimidinyl]-, diethyl ester NSC704885