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

Participants

Reaction Conditions

Reaction Steps

To a mixture of 4-{[1-(3-bromo-5-chloro-phenyl)-methylidene]-amino}-benzoic acid ethyl ester (6.4 g, 17.5 mmol) and ytterbium(III) triflate hydrate (1.08 g, 1.75 mmol) in dry tetrahydrofuran (50 mL) at 25° C. was added isobutyraldehyde (1.59 mL, 17.5 mmol) and water (0.32 mL, 17.5 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-chloro-phenyl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (7.67 g, 100%) as a light yellow oil: LC/MS m/e calcd for C20H21BrClNO3 M+: 438.8, observed: 438.8, 440.8.

Provenance & Evidence