Water → BendaMustine IMpurity C

Participants

Reaction Conditions

Reaction Steps

4-{5-[Bis-(2-hydroxyethyl)amino]-1-methyl-1H-benzimidazol-2-yl}-butyric acid isopropyl ester (5 g) and dichloromethane (75 mL) are charged into a round bottom flask and cooled to 0-5° C. Thionyl chloride (4 mL, 4.0 M) is slowly added at the same temperature. The temperature is allowed to rise to 25-30° C. and the mixture is stirred for about 7 hours. Water (100 mL) is slowly added and the mixture is stirred for about 20 minutes, then the layers are separated. The dichloromethane layer is washed with saturated sodium bicarbonate solution (100 mL), dried over sodium sulfate, and is concentrated under vacuum at 30-33° C. to obtain 10-15 mL of a concentrated mass. n-Heptane (100 mL) is added to the concentrated mass slowly at 27° C., stirred for about 1 hour, filtered, and the collected solid is washed with n-heptane (15 mL) and dried under vacuum to give the title compound. Yield: 3.4 g (61%).

Provenance & Evidence