Hydrochloric Acid → tert-butyl 7-acetyl-2,3,4,5-tetrahydro-1H-3-benzazepine-3-carboxylate

Participants

Reaction Steps

To a stirred solution of 3-(tert-butyloxycarbonyl)-7-trifluoromethylsulfonyloxy-2,3,4,5-tetrahydro-1H-3-benzazepine (10 g, 25.3 mmol) in anhydrous dimethylformamide (100 ml) under argon at room temperature, was added triethylamine (7.05 ml, 50.6 mmol), butyl vinyl ether (16.4 ml, 126.6 mmol), 1,3-bis(diphenylphosphino)propane (0.412 g, 1 mmol) and palladium acetate (0.202 g, 0.9 mmol) sequentially. The resultant mixture was heated at 85° C. for 1.5 h and cooled to room temperature. 4% Aqueous hydrochloric acid (150 ml) was added and stirring continued for 0.5 h. The reaction mixture was extracted with dichloromethane (3×300 ml) and the combined organics washed with water (4×500 ml), dried (Na2SO4) and evaporated in vacuo to afford a brown gum. Chromatography on silica gel with 0-30% ethyl acetate—hexane gradient elution gave the title compound (5.8 g, 79%) as a colourless solid.

Provenance & Evidence