Trifluoroacetic acid → Ethyl 6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylate

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Reaction Steps

A stirred solution of 18.4 g (0.05 mol) 6-bromo-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester in 165 mL dichloromethane was cooled to 0 deg C. and then 38.0 mL trifluoroacetic acid was added over 5 min. The cooling bath was removed and after 2 h at room temperature the reaction mixture was poured into 500 mL saturated aqueous sodium bicarbonate solution. The organic layer was extracted three times with 150 mL portions of dichloromethane; the combined organic phases were washed with 200 mL brine, dried over magnesium sulfate and filtered. The solvent was evaporated and the residue was dried under high vacuum to give 12.0 g (95.5%) of the desired product as a colourless solid.

Provenance & Evidence