Triethylamine → N-[(Phenylmethoxy)carbonyl]-L-valyl-L-leucine methyl ester

Participants

Reaction Conditions

Reaction Steps

19.9 g (110 mmols) of H-Leu-OMe. HCl are dissolved in 120 ml of dimethylformamide and 14.6 ml (105 mmols) of triethylamine are added at 0°C. The precipitated triethylamine hydrochloride is filtered off, the filtrate is added to a solution of 25.1 g (100 mmols) of Z-Val-OH in 200 ml of dimethylformamide (0°C), and 22.6 g (110 mmols) of dry dicyclohexylcarbodiimide are then added. After 1 hour's stirring at 0°C and standing overnight in the refrigerator the mixture is filtered and the solution evaporated in a high vacuum at 40°C. The oily residue is taken up in 30 ml of ethyl acetate, and the solution is cooled to 0°C and freed of precipitated dicyclohexylurea. After adding n-hexane the product crystallises out from the filtrate overnight. Melting point 102°-105°C; [α]D : -41° (c = 2.88 in methanol).

Provenance & Evidence