4-Carbamoyl-2(R,S)-α-naphthoxybutyric acid: 1.49 ml of 1,8-diazabicyclo[5.4.0]undec-7-ene are added to a solution of 3 g of α-naphthoxymalonic acid diethyl ester (Example 36a) and 0.71 g of acrylamide in 5 ml of acetonitrile and the whole is stirred at room temperature for 24 hours. 25 ml of water are added to the reaction mixture, which is adjusted to pH 2 with 2N hydrochloric acid and extracted with ether. The ethereal phases are washed with water and brine, dried over sodium sulphate and concentrated by evaporation, leaving (2-carbamoylethyl)-α-naphthoxymalonic acid diethyl ester.
