Hydrochloric Acid → 9-[(2-Fluorophenyl)methyl]-4-hydroxy-5-carbamoyl carbazole

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Reaction Steps

A solution of the 9-[(2-fluorophenyl)methyl]-4-hydroxy-5-carbomethoxy carbazole (237.5 mg, 0.68 mM) in 10 mL THF and 40 mL concentrated aqueous ammonium hydroxide was sonicated for 20 h at 40-50° C. The mixture was diluted with ethyl acetate and acidified to pH 1 with 5 N HCl. The aqueous layer was extracted twice with ethyl acetate. The combined organic extracts were washed with saturated brine, dried over magnesium sulfate, filtered, and concentrated. The residue was purified by column chromatography on silica gel (elution with gradient methylene chloride/ethyl acetate) to afford 89.7 mg (40%) of the 9-[(2-fluorophenyl)methyl]-4-hydroxy-5-carbamoyl carbazole as a white solid. 1H NMR (DMSO-d6) δ10.5 (s, 1H), 8.8 (br s, 1H), 8.4 (br s, 1H), 7.8 (dd, 1H, J=1 and 8 Hz), 7.5-6.9 (m, 7H), 6.65 (m, 2H), and 5.75 (s, 2H). IR (KBr, cm−1) 3395, 3192 (br), 1621, 1599, 1580, 1564, 1491, 1455, 1334, 1261, and 774. MS (ES) m/e 333, 335.

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