Dicyclohexylcarbodiimide → Trt-Cys(Trt)-Cys(Acm)-Thr(But)-Ser(But)-OMe

Participants

Reaction Steps

5.43 g of Trt-Cys(Trt)-Cys(Acm)-OH and 2.33 g of H-Thr(But)-Ser(But)-OMe are dissolved in 70 ml of ethyl acetate and 1.55 g of dicyclohexylcarbodiimide and 1.02 g of N-hydroxybenzotriazole are added at 0°C. After 4 hours at 0°C and 17 hours at 4°C, the mixture is filtered and the solution is diluted with 200 ml of ethyl acetate and washed with 1 N citric acid, 1 N sodium bicarbonate and water. After drying over sodium sulphate, the solution is evaporated and the residue is reprecipitated from ether acetatepetroleum ether.

Provenance & Evidence