Water → N-[5-bromo-2-(2,3-dihydro-1H-indol-1-yl)phenyl]-N',N'-dimethylurea

Participants

Reaction Steps

To a stirred mixture, under nitrogen, of 28.9 g (0.10 mole) of 1-(2-amino-4-bromophenyl)indoline hydrochloride and 16.8 g (0.20 mole) of anhydrous powdered sodium bicarbonate in 500 ml of chloroform was added a solution of 21.5 g (0.20 mole) of dimethylcarbamyl chloride in 25 ml of chloroform, over a 10 minute period. The mixture was heated under reflux for 7 hours, and 8.4 g (0.10 mole) of sodium bicarbonate and 10.7 g (0.10 mole) of the dimethylcarbamyl chloride were added. After heating under reflux for 2 days, equivalent amounts (8.4 g of sodium bicarbonate and 10.7 g of dimethylcarbamyl chloride) were added. After three days under reflux, the mixture was cooled and 500 ml of water was added. The phases were stirred vigorously for 0.5 hours and separated. The organic phase was washed three times with water, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was dissolved in 200 ml of dichloromethane and adsorbed on a chromatography column containing 1 kg of silica gel packed in and eluted with dichloromethane. The fractions containing product were combined and concentrated to afford 14.5 g (40%) of product. Recrystallization from toluene (charcoal)/hexane gave the analytical sample, mp 119°-121° C.

Provenance & Evidence