[CH3:1][C:2]1[CH:3]=[C:4]([CH2:8][N:9]2[C:21]3[CH:20]=[CH:19][CH:18]=[C:17]([OH:22])[C:16]=3[C:15]3[C:10]2=[CH:11][CH:12]=[CH:13][C:14]=3[C:23]([O:25]C)=O)[CH:5]=[CH:6][CH:7]=1.Cl.[OH-].[NH4+:29]>C1COCC1.C(OCC)(=O)C>[CH3:1][C:2]1[CH:3]=[C:4]([CH2:8][N:9]2[C:21]3[CH:20]=[CH:19][CH:18]=[C:17]([OH:22])[C:16]=3[C:15]3[C:10]2=[CH:11][CH:12]=[CH:13][C:14]=3[C:23](=[O:25])[NH2:29])[CH:5]=[CH:6][CH:7]=1A solution of the 9-[(3-methylphenyl)methyl]-4-hydroxy-5-carbomethoxy carbazole (300 mg, 0.87 mM) in 10 mL THF and 30 mL concentrated aqueous ammonium hydroxide was sonicated for 5 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 114 mg (40%) of the 9-[(3-methylphenyl)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), 7.8 (dd, 1H, J=1 and 8 Hz), 7.4 (m, 2H), 7.3 (t, 1H, J=8 Hz), 7.15-7.0 (m, 3H), 6.85 (d, 1H, J=8 Hz), 6.6 (d, 1H, J=8 Hz), 5.95 (d, 1H, J=8 Hz), 5.65 (s, 2H), and 2.25 (s, 3H). IR (KBr, cm−1) 3434, 3203, 1629, 1599, 1579, 1552, 1443, 1330, 1262, 1214, and 776. MS (ES) m/e 329, 331.
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