Trifluoroacetic acid → 2-(3-Bromo-5-chloro-phenyl)-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester

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Reaction Conditions

Reaction Steps

To a mixture of 2-(3-bromo-5-chloro-phenyl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (7.67 g, 17.5 mmol) and triethylsilane (10 mL) at 25° C. was added trifluoroacetic acid (5 mL) dropwise. The resulting mixture was stirred at 25° C. for 1 h. Then the reaction mixture was concentrated in vacuo and the residue was extracted with ethyl acetate (2×100 mL), washed with saturated aqueous sodium bicarbonate solution (2×50 mL), dried over anhydrous sodium sulfate and concentrated in vacuo. Purification on flash silica gel chromatography (silica gel from QingDao, 200-300 mesh, glass column from Shanghai SD company)(10% ethyl acetate/hexanes) to afford 2-(3-bromo-5-chloro-phenyl)-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (3.12 g, 42%) as a white solid: LC/MS m/e calcd for C20H21BrClNO2 M+: 422.8, observed: 422.0, 424.0.

Provenance & Evidence