METHOD FOR REDUCING 3-DIMETHYLAMINO-2-PHENYLPROPION-ACID ETHYL ESTER-CONTENT IN SOLUTIONS OF 2-DIMETHYLAMINO-1-PHENYL-3-CYCLOHEXENE-1-CARBOXYLIC ACID ETHYL ESTER

摘要

A process for reducing the content of ethyl 3-dimethylamino-2-phenylpropionate in a solution, contaminated therewith, of ethyl 2-dimethylamino-1-phenyl-3-cyclohexene-1-carboxylate in a water-immiscible solvent, which comprises adding from 0.5 to 2.0 equivalents of a carboxylic acid per mole of ethyl 2-dimethylamino-1-phenyl-3-cyclohexene-1-carboxylate to this solution, and stirring this mixture at a temperature of from 50° C. to 100° C., is described.