Water → methyl 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,2-a][1,4]benzodiazepine-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

1.40 g of methyl 2-[7-chloro-5-(2-fluorophenyl)-3H-1,4-benzodiazepin-2-ylamino]-3-oxo-butyrate were taken up in 10 ml of dimethylformamide, 100 mg of p-toluenesulphonic acid monohydrate were added and the mixture was stirred at 80° C. for 2 h. For the working up the mixture was treated with 30 ml of water and extracted 5 times with 50 ml of diethyl ether each time. The combined organic phases were dried over magnesium sulphate, concentrated in a vacuum and purified by chromatography on 70 g of silica gel with dichloromethane containing 2% methanol. There were obtained 550 mg (41%) of methyl 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,2-a][1,4]benzodiazepine-2-carboxylate of m.p. 137-138° C. which was used without further purification for the step described below.

Provenance & Evidence