反应详情

温度

25 °C

A solution of compound (5) (58 g, 0.1053 mol) in dichloromethane (500 ml) was stirred at 25° C. under argon atmosphere. N-(tert-butoxycarbonyl)-L-valine (29.7 g, 0.1367 mol), 1-[3-(dimethylamino) propyl]-3-ethylcarbodiimide hydrochloride (26.2 g, 0.1367 mol) and 4-(dimethylamino)pyridine (1.3 g, 0.0106 mol) were added and the reaction mixture was stirred at 25° C. and monitored by HPLC (method #2). After 4 hours, HPLC showed 7.9% of starting material. N-(tert-butoxycarbonyl)-L-valine (4.57 g, 0.0210 mol) and 1-[3-(dimethylamino) propyl]-3-ethylcarbodiimide hydrochloride (4.03 g, 0.0210 mol) were added and stirring was continued at 25° C. for an additional period of 2 hours, after which, HPLC detected 0.7% of starting material. Methanol (60 ml) was added to the reaction mixture and solvents were evaporated under reduced pressure (temperature kept below 40° C.) to give compound (6) as thick oil. This material (93% pure by HPLC/AUC) was used as is for the subsequent reaction.

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2. waitwas continued at 25° C. for an additional period of 2 hours
3. customwere evaporated under reduced pressure (temperature kept below 40° C.)