Dicyclohexylcarbodiimide → Fmoc-Tyr(tBu)-Cys(Trt)-Asn-OtBu

Participants

Reaction Conditions

Reaction Steps

1.63 g of DCC are added to a stirred solution of 3.4 g of Fmoc-Tyr(tBu)-OH, 3.95 g (7.4 mmol) of H-Cys(Trt)-Asn-OtBu (Liebigs Ann. Chem. 1979, 242) and 1 g of HOBT in 50 ml of dimethylformamide at 0° C., and the mixture is left to stir at 0° C. for 1 h and to stand at room temperature overnight. The next day, the precipitate is filtered off with suction and the filtrate is concentrated. The residue is triturated with ethyl acetate. Yield 2.83 g. A further 3.63 g can be isolated from the mother liquor. Total yield: 6.46 g (89%).

Provenance & Evidence