Dicyclohexylcarbodiimide → HCID 178501424, compound

Participants

Reaction Conditions

Reaction Steps

A slurry of 36.4 g. L-histidine methyl ester dihydrochloride in dichloromethane (1 1.) was cooled to 5° C. and treated with 52 ml. triethylamine. After 10 minutes 40 g. Boc-L-phenylalanine was added followed by 1-hydroxybenzotriazole (30.6 g.), then after another 5 minutes by dicyclohexylcarbodiimide (30.8 g.), and the mixture was stirred at 0° C. for 4 hours and at 20° C. for 90 hours. The mixture was then filtered and the filtered solid was washed with dichloromethane, and the combined organic layers were concentrated and the residue was dissolved in 1 1. ethyl acetate. After 10 minutes of stirring the mixture was filtered and the filtrate was washed with 1N sodium hydroxide (3×150 ml.), brine, dried over magnesium sulfate and concentrated giving 45.9 g. of a colorless solid which was used without additional purification in Step B.

Provenance & Evidence