1-Oxa-3-azaspiro(4.7)dodecane-3-carboxylic acid, 2-oxo-, 2-(dimethylamino)ethyl ester, fumarate (1:1) 7621-11-6 Dimethylaminoethyl 2-oxo-1-oxa-3-azaspiro(4.7)dodecane-3-carboxylate fumarate Oxa-1 oxo-2 aza-3 (dimethylamino ethoxy carbonyl)-3 spiro(4.7)dodecane, fumarate [French]