Hydrochloric Acid → 9-[(3-Trifluoromethoxyphenyl)methyl]-4-hydroxy-5-carbamoyl carbazole

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Reaction Steps

A solution of the 9-[(3-trifluoromethoxyphenyl)methyl]-4-hydroxy-5-carbomethoxy carbazole (260 mg, 0.62 mM) in 10 mL THF and 30 mL concentrated aqueous ammonium hydroxide was stirred vigorously for 132 hours. The mixture was diluted with ethyl acetate and acidified to pH 1 with 5 N HCl. The aqueous layer was extracted three times with ethyl acetate. The combined organic extracts were washed with H2O and saturated brine, dried over magnesium sulfate, filtered, and concentrated. The residue was purified by column chromatography on silica gel (elution with gradient hexanes/ethyl acetate) to afford 150 mg (60%) of the 9-[(3-trifluoromethoxyphenyl)methyl]-4-hydroxy-5-carbamoyl carbazole as an off-white solid. 1H NMR (DMSO-d6) δ 10.5 (s, 1H), 8.8 (br s, 1H), 8.4 (br s, 1H), 7.85 (dd, 1H, J=1 and 8 Hz), 7.5-7.15 (m, 5H), 7.1 (d, 1H, J=8 Hz), 7.0 (d, 1H, J=8 Hz), 6.6 (d, 1H, J=8 Hz), 5.95 (d, 1H, J=8 Hz), and 5.65 (s, 2H). IR (KBr, cm−1) 3431, 3203, 1629, 1601, 1580, 1548, 1446, 1330, 1261, 1215, and 777. MS (ES) m/e 399, 401.

Provenance & Evidence