Water → 2-(3-Bromo-phenyl)-6-chloro-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-8-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mixture of 2-{[1-(3-bromo-phenyl)-methylidene]-amino}-5-chloro-benzoic acid methyl ester (5.3 g, 15 mmol) and ytterbium(III) triflate hydrate (0.93 g, 1.5 mmol) in dry tetrahydrofuran (10 mL) at 25° C. was added isobutyraldehyde (1.08 g, 15 mmol) and water (0.27 mL, 15 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-phenyl)-6-chloro-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-8-carboxylic acid methyl ester (6.4 g, 100%) as a light yellow oil: LC/MS m/e calcd for C19H19BrClNO3 M+: 424.7, observed: 408.0.

Herkunft & Nachweise