Water → 2-(3-Bromo-5-fluoro-phenyl)-4-hydroxy-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 4-{[1-(3-bromo-5-fluoro-phenyl)-methylidene]-amino}-benzoic acid ethyl ester (2.25 g, 6.43 mmol) and ytterbium(III) triflate hydrate (0.40 g, 0.64 mmol) in dry tetrahydrofuran (10 mL) at 25° C. was added isobutyraldehyde (0.59 mL, 6.43 mmol) and water (0.12 mL, 6.43 mmol) dropwise. The reaction mixture was stirred at 25° C. for 5 h. Then the reaction mixture was concentrated in vacuo and the residue was extracted with ethyl acetate (2×100 mL), washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to afford 2-(3-bromo-5-fluoro-phenyl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (2.33 g, 86%) as a light yellow oil: LC/MS m/e calcd for C20H21BrFNO3 M+: 422.3, observed: 404.3, 406.3.

Provenance & Evidence