Acetic Acid → cis-4-(3,5-Bis-trifluoromethyl-benzylamino)-6-hydroxy-7-methoxy-2-methyl-3,4-dihydro-2H-quinoline-1-carboxylic acid ethyl ester

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Reaction Steps

To a stirred suspension of cis-4-amino-6-hydroxy-7-methoxy-2-methyl-3,4-dihydro-2H-quinoline-1-carboxylic acid ethyl ester (387 mg, 1.38 mmol) in dichloromethane (9 mL) was added 3,5-bis(trifluoromethyl)benzaldehyde (225 μL, 1.38 mmol), followed by acetic acid (80 μL, 1.4 mmol). The reaction was stirred at room temperature for 1 h, then sodium triacetoxyborohydride (440 mg, 2.08 mmol) was added. The reaction was stirred at room temperature for 5 h. Water (5 mL) was added, and the mixture was slowly basified to pH 10 with solid potassium carbonate. The mixture was then extracted with ethyl acetate (3×10 mL), the combined organic phases were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 680 mg crude product. Purification by silica gel chromatography using 0-25% ethyl acetate/hexanes as eluent afforded 458 mg of the title compound (65%).

Provenance & Evidence