Triethylamine → N-(2-ethylthioethyl)-glycine tert-butyl ester

To a solution of 10 g of 2-ethylthioethylamine hydrochloride and 15 g of triethylamine in 20 ml of chloroform was added with stirring 11 g of tert-butyl chloroacetate over a period of 30 minutes, while maintaining the temperature at 30°-70° C. The reaction mixture was held at 70° C for an addition 1 hour. At the end of this period, the chloroform was evaporated in vacuo, and the residue was taken up in 40 ml of 2N NaOH solution and 50 ml of benzene, transferred into a separatory funnel and well shaken. The benzene solution was separated, washed with water, dried over anhydrous sodium sulfate and filtered. After evaporation of benzene, the residue was distilled under reduced pressure to give 5.3 g (34 percent) of N-(2-ethylthioethyl)glycine tert-butyl ester, B.P. 106°-9° C/1.5 mm Hg.