Water → 7-chloro-2,3,4,5-tetrahydro-1H-1-benzazepin-5-one

Participants

Reaction Conditions

Reaction Steps

7-Chloro-1-p-toluenesulfonyl-2,3,4,5-tetrahydro-1H-1-benzazepin-5-one (5 g) is added to 90% (w/w) sulfuric acid (50 ml), and the mixture is stirred at 0° C. to 10° C. for 2.5 hours. The reaction mixture is added to a cool water (50 mL) and then is neutralized by gradually adding thereto a solution of sodium hydroxide (75 g) in an appropriate amount of water with attention to exothermal reaction. The reaction mixture is cooled to 25° C., and the resulting yellowish green suspension is extracted with toluene (50 mL), and the organic layer is separated, washed with water (25 ml×2) and dried over sodium sulfate. After filtering off sodium sulfate, the filtrate is concentrated under reduced pressure to give a pale yellow crystals. The crystals are subjected to azeotropic dehydration with toluene in order to remove a slight amount of water to give 7-chloro-2,3,4,5-tetrahydro-1H-1-benzazepin-5-one having a moisture content of less than 100 ppm (2.5 g, yield 89%, M.p. 103-104° C.).

Provenance & Evidence