1-(9-Oxobicyclo(3.3.1)non-2-yl)-4-phenyl-4-piperidinecarboxylic acid ethyl ester maleate 36576-73-5 4-Piperidinecarboxylic acid, 1-(9-oxobicyclo(3.3.1)non-2-yl)-4-phenyl-, ethyl ester, maleate