Methanol → Methyl 7-hydroxy-3-methyl-6-(methylsulfonyl)-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylate

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Reaction Steps

DMF (5 drops) was added to a suspension of 7-hydroxy-3-methyl-6-(methylsulfonyl)-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid (6.92 g, 16.27 mmol) in dichloromethane (120 mL) at 0° C. Oxalyl chloride (2.14 mL, 24.40 mmol) was added slowly. After 1 h at 0° C., the mixture was warmed to room temperature and additional oxalyl chloride (2.14 mL, 24.40 mmol) was added. The mixture was warmed to room temperature and stirred overnight. Methanol (30 mL) was added and the mixture stirred overnight. The solvent was removed under reduced pressure, the residue was diluted with water, and the aqueous mixture was treated with saturated aqueous NaHCO3. The mixture was extracted with methylene chloride (three times). The combined organic extracts were washed with brine (2 times), dried over Na2SO4, filtered, and concentrated to afford methyl 7-hydroxy-3-methyl-6-(methylsulfonyl)-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylate (6.0 g, 84% yield). 1H NMR (400 MHz, DMSO-d6) δ 11.85 (br. s., 1H), 8.18 (s, 1H), 7.95-8.02 (m, 2H), 7.91 (d, J=7.78 Hz, 1H), 7.78 (t, J=7.78 Hz, 1H), 7.55 (s, 1H), 4.07 (s, 3H), 3.41 (s, 3H), 2.32 (s, 3H); MS (m/z) 440.0 (M+H+).

Provenance & Evidence