Dicyclohexylcarbodiimide → HCID 131715031, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 3.5 g of Boc-Ile (16 mmol) is reacted with 3.8 g of 1-hydroxybenzotriazole (2.4 mmol) and 3.7 g of N,N'-dicyclohexylcarbodiimide (18 mmol) for 1 hour at 0° C., and then the solution of Pro-Tyr-OMe in 15 cm3 of dimethylformamide, prepared earlier, is added. After stirring for 1 hour at 0° C. and then for 10 hours at 20° C., the precipitate of dicyclohexylurea is separated off by filtration and the filtrate is concentrated. The residue obtained is dissolved in ethyl acetate and the solution obtained is washed successively with a 1M solution of citric acid, a solution of sodium bicarbonate and a solution of sodium chloride. The organic layer is dried over sodium sulphate. After removal of the solvent, the crude product is purified by chromatography on a column of silica gel (height 45 cm, diameter 2.5 cm), by eluting with ethyl acetate and mixtures of ethyl acetate with hexane. 3.8 g of Boc-Ile-Pro-Tyr-OMe are obtained, the properties of which are as follows:

Provenance & Evidence