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

The invention relates to a method for reducing the content of 3-dimethylamino-2-phenylpropionic acid ethyl ester in a solutionthat is contaminated therewith, whereby the solution is 2-dimethylamino-1-phenyl-3-cyclohexene-1-carboxylic acid ethyl ester, ina solvent which cannot be mixed with water. According to the invention, 0.5 to2.0 equivalents of a carboxylic acid per mol2-dimethylamino-1-phenyl-3-cyclohexene-1-carboxylic acid ethyl ester is addedto the solution and this mixture is stirred at a temperatureof 50 °C to 100 °C.