Manufacturing Process
A suspension of 1-[7,8-dimethoxy-1,3-dihydro-2H-3-benzazepin-2-on-3-yl]-3-
(N-benzylmethylamino)propane and 10% palladium-on-charcoal in glacial
acetic acid was hydrogenated at 50°C and at a hydrogen pressure of 5 bar.
After the catalyst had been filtered off, the solvent was evaporated in vacuum,
and the residue was taken up in methylene chloride. After the solution had
been extracted with an aqueous sodium bicarbonate solution and washed with
water, it was dried over magnesium sulfate, evaporated and purified over
silica gel with methylene chloride and then with increasing amounts of
methanol (up to 10%). The N-[3-(7,8-dimethoxy-1,3,4,5-tetrahydro-2H-3-
benzazepin-2-one-3-yl)propyl]methylamine hydrochloride. Yield: 87% of
theory. Melting point: 110°C (dec.).
1.26 g (20 mmols) of sodium cyanoborohydride were added to a solution of
3.29 g (10 mmols) of N-[3-(7,8-dimethoxy-1,3,4,5-tetrahydro-2H-3-
benzazepin-2-one-3-yl)propyl]methylamine hydrochloride and 1.8 g (10
mmol) of 2-(3,4-dimethoxyphenyl)acetaldehyde in 40 ml of ethanol, while
maintaining a pH of 6-7 by the addition of 2 N hydrochloric acid, and stirring
was continued for 48 h at room temperature. After evaporating the solution in
vacuum, the residue was taken up in dilute hydrochloric acid and extracted
twice with ether. Subsequently, the aqueous phase was made alkaline and
extracted three times with methylene chloride, and the organic phase was
evaporated and purified on silica gel. The 1-[7,8-dimethoxy-1,3,4,5-
tetrahydro-2H-3-benzazepin-2-on-3-yl]-3-[N-methyl-N-(2-{3,4-
dimethoxyphenyl}ethyl)amino]propane was obtained.
