Triethylamine → BOC-(D)Trp-Lys(Z)-OMe

Participants

Reaction Conditions

Reaction Steps

9.8 ml NEt3, 11.8 g HOBT and 21.3 g BOC-(D)Trp-OH are added to 23.3 g H-Lys(Z)-OMe hydrochloride in 300 ml DMF, and the solution cooled to -15° C. 15.6 g DDCI in 50 ml DMF are added and the reaction mixture stirred for ca. 16 hrs. at 0° C., followed by 2 hrs. at room temperature. The reaction mixture is diluted with AcOEt/ethyl-ether and the dicyclohexyl-urea is filtered off. The filtrate is washed with 2 N citric acid, H2O, 10% KHCO3 solution and 30% NaCl solution. The organic phase is dried over Na2SO4 and concentrated strongly under vacuum. Crystallisation is effected by the addition of ethyl-ether/hexane and the product is filtered off, washed with ethyl-ether/hexane and dried to yield the title compound:

Provenance & Evidence