Diisopropylethylamine → 3({6-[17-(1,5-Dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yloxycarbonylamino]-hexanoyl}ethoxycarbonylmethyl-amino)-propionic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

The hydrochloride salt of 3-[(6-Amino-hexanoyl)-ethoxycarbonylmethyl-amino]-propionic acid ethyl ester AC (4.7 g, 14.8 mmol) can be taken up in dichloromethane. The suspension was cooled to 0° C. on ice. To the suspension diisopropylethylamine (3.87 g, 5.2 mL, 30 mmol) can be added. To the resulting solution cholesteryl chloroformate (6.675 g, 14.8 mmol) can be added. The reaction mixture can be stirred overnight. The reaction mixture can be diluted with dichloromethane and washed with 10% hydrochloric acid. The product can be purified by flash chromatography (10.3 g, 92%).

Provenance & Evidence