Ethyl bromoacetate → 3-bromo-1-ethoxycarbonylmethyl-2,3,4,5-tetrahydro-1H-1-benzazepin-2-one

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Reaction Steps

A solution of 20 g of 3-bromo-2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepine in 50 ml of dimethylformamide at 65° is added to a suspension of 114.7 g of potassium carbonate in 200 ml of dimethylformamide at room temperature maintaining the temperature of the reaction mixture below 30°. The reaction mixture is then stirred at room temperature for 90 minutes. A solution of 20.7 g of ethyl bromoacetate in 50 ml of dimethylformamide is added over a period of 30 minutes at room temperature. The reaction mixture is then stirred at 55° for one hour, filtered, the filter cake is washed with 100 ml of dimethylformamide, and the filtrate is evaporated to a small volume (removing about 200 ml of dimethylformamide) at 65° and 40 mm Hg. After cooling to 5°, 250 ml of water is added over a one hour period, maintaining the temperature below 10°, and the suspension is stirred at about 5° for 15 minutes. The solid is filtered off, washed with 200 ml of cyclohexane, and dried at 55° and 40-60 mm for 16 hours to give 3-bromo-1-ethoxycarbonylmethyl-2,3,4,5-tetrahydro-1H-1-benzazepin-2-one.

Provenance & Evidence