Acetic Acid → Indole

Reaction equation

CC(=O)CCC(=O)C.CN1CC=C([C:16]2[C:24]3[C:19](=[CH:20][CH:21]=[C:22](N)[CH:23]=3)[N:18](S(C3C=CC=CC=3)(=O)=O)[CH:17]=2)CC1.C(O)(=O)C>C(O)C>[NH:18]1[C:19]2[C:24](=[CH:23][CH:22]=[CH:21][CH:20]=2)[CH:16]=[CH:17]1

Participants

Procedure

Hexane-2,5-dione (2 mL) was added to a solution of 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1-(phenylsulfonyl)-1H-indol-5-amine (300 mg, 0.82 mmol) in ethanol (50 mL). Acetic acid (2 mL) was added, and the resulting solution was stirred at room temperature overnight. The solvent was concentrated, followed by column chromatography purification using a 1:10 methanol/dichloromethane solvent system provided 30 mg (8%) of 5-(2,5-dimethyl-1H-pyrrol-1-yl)-3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1-phenylsulfonyl)-1H-indole as a yellow solid. 1H NMR (CDCl3) δ 8.05 (d, 1H), 7.95 (d, 2H), 7.62 (s, 1H), 7.50 (d, 2H), 7.26 (2H), 6.84 (d, 2H), 6.11 (s, 1H), 5.90 (s, 2H), 3.46 (d, 2H), 3.07 (t, 2H), 2.74 (s, 2H), 2.62 (s, 2H), 1.98 (s, 6H). LC/MS (EI) tR 2.46, m/z 446.0 (M++1)