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

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Reaction Steps

A solution of the 9-[(3-cyanophenyl)methyl]-4-hydroxy-5-carbomethoxy carbazole (114 mg, 0.32 mM) in 5 mL THF and 20 mL concentrated aqueous ammonium hydroxide was sonicated for 7 hours 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 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 40 mg (49%) of the 9-[(3-cyanophenyl)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 (d, 1H, J=8 Hz), 7.7 (d, 1H, J=8 Hz), 7.6 (s, 1H), 7.5-7.4 (m, 3H), 7.3 (t, 1H, J=8 Hz), 7.25 (d, 1H, J=8 Hz), 7.1 (d, 1H, J=8 Hz), 6.6 (d, 1H, J=8 Hz), and 5.75 (s, 2H). IR (KBr, cm−1) 3430, 3347, 2231, 1628, and 1601. MS (ES) m/e 340, 342.

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