Triethylamine → HCID 178501424, compound

Participants

Reaction Steps

43.73 g (164 mmol) of N-tert.-butoxycarbonyl-L-phenylalanine and 34.5 g (142 mmol) of L-histidine methyl ester dihydrochloride are taken in 400 ml of methylene chloride. 100 g (1 mol) of triethylamine are added at -20° C. (acetone/dry ice bath), while stirring. 111 ml (0.171 mol) of propanephosphonic acid anhydride solution (50% strength in methylene chloride) are now added dropwise to the cooled mixture. The mixture is allowed to warm to room temperature overnight. The solvent is stripped off and the crude product is taken up in 500 ml of ethyl acetate. The organic phase is washed 4 times with 200 ml of saturated sodium bicarbonate solution each time, 3 times with 0.1N hydrochloric acid and once with saturated sodium chloride solution, dried over magnesium sulphate and concentrated in vacuo.

Provenance & Evidence