Tetrahydrofuran → 2-(3-dimethylaminopropylthio)-5-(2-chlorophenyl)-7-chloro-3H-1,4-benzodiazepine

Participants

Reaction Conditions

Reaction Steps

To a solution of 3.2 g of 1,3-dihydro-5-(2-chlorophenyl)-7-chloro-2H-1,4-benzodiazepine-2-thione in a solvent mixture comprising 17 ml of a 10% aqueous potassium hydroxide solution and 1.2 ml of tetrahydrofuran are added at room temperature with stirring 1.75 g of N,N-dimethyl-3-chloropropylamine hydrochloride and 100 mg of benzyltriethylammonium chloride, and the resulting mixture is stirred on a water bath at 40° C. for 4 hours. The reaction mixture is diluted with water and extracted with ethyl acetate. The extract is washed with water and dried over magnesium sulfate and, thereafter, the solvent is distilled off under reduced pressure to obtain an oily 2-(3-dimethylaminopropylthio)-5-(2-chlorophenyl)-7-chloro-3H-1,4-benzodiazepine. The oily product thus obtained is treated, according to usual procedure, with fumaric acid and recrystallized from isopropyl alcohol to obtain 4.40 g of 2-(3-dimethylaminopropylthio)-5-(2-chlorophenyl)-7-chloro-3H-1,4-benzodiazepine fumarate, m.p. 154°-156° C.

Provenance & Evidence