Potassium Hydroxide → 57616-48-5

Participants

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 is added at room temperature with stirring 2.16 g of N,N-dimethyl-2-chloroethylamine hydrochloride in its powdery form. The resulting mixture is stirred at room temperature for 3 hours and, thereafter, the reaction mixture is diluted with water and extracted with ethyl acetate. The extract is washed with water, dried and then distilled under reduced pressure to remove the solvent, whereby an oily 2-(2-dimethylaminoethylthio)-5-(2-chlorophenyl)-7-chloro-3H-1,4-benzodiazepine is obtained. The oily product thus obtained is treated, according to usual procedure, with maleic acid and recrystallized from an isopropyl alcohol-acetone mixture to obtain 4.50 g of 2-(2-dimethylaminoethylthio)-5-(2-chlorophenyl)-7-chloro-3H-1,4-benzodiazepine maleate, m.p. 140°-142° C.

Provenance & Evidence