3-Cyclohexene-1-carboxylic acid, 2-(dimethylamino)-1-phenyl-, ethyl ester, trans-(+-)-, (E)-2-butenedioate (1:1) 55567-81-2 EINECS 259-711-1 Tilidine fumarate trans-(1)-(2-(Ethoxycarbonyl)-2-phenylcyclohex-5-enyl)dimethylammonium hydrogen fumarate