1,2-Dichloroethane → ethyl 6-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-3-carboxylate

Participants

Reaction Steps

To a light suspension of 6-bromo-3-(ethoxycarbonyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acid (2.12 g, 5.79 mmol), EDC (1.332 g, 6.95 mmol), and 1-hydroxybenzotriazole hydrate (1.064 g, 6.95 mmol) in THF/CH2Cl2 (5/1) (100 mL) was added ammonium hydroxide (1.353 mL, 34.7 mmol) and it turned into a thick light yellow suspension and it was stirred at rt overnight. The reaction was concentrated and the residue was dissolved in water/ethyl acetate. The organic phase was separated and washed with brine, dried over Na2SO4, filtered, concentrated to afford the crude product as a light yellow solid, which was washed with a small amount of ether and air-dried. The crude ethyl 6-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-3-carboxylate was used as such in the next reaction.

Provenance & Evidence