HCID 23356894, compound → HCID 53970794, compound

Participants

Reaction Steps

A solution of 0.73 g (3 mmol) of the compound from Example VI in 5 ml of ethyl acetate is added at 0° C. to a solution of 0.93 g (2.16 mmol) of (S)-isoleucine methyl ester isocyanate (prepared by reacting (S)-isoleucine methyl ester hydrochloride with trichloromethyl chloroformate in toluene at 120° C.) in 10 ml of ethyl acetate, and the mixture is stirred at this temperature for 30 min. Subsequently, the reaction mixture is washed successively with dilute hydrochloric acid, water and saturated solutions of sodium hydrogen carbonate and sodium chloride, and the organic phase is then concentrated and the residue purified on silica gel using petroleum ether/ethyl acetate (2:1).

Provenance & Evidence