Methanol → 2-methyl-1H-indol-5-ol

Participants

Reaction Steps

A solution of 5-Methoxy-2-methyl-1H-indole (2 g, 12.4 mmol) in 10 mL dichloromethane was cooled to −78° C. A 1.0 M solution of BBr3 in dichloromethane (30 mL, 30.0 mmol) was added and the resultant mixture was stirred at −78° C. for three hours. The reaction was carefully quenched into ice water and extracted with dichloromethane two times. The combined organic layers were washed with brine, dried over magnesium sulfate, and evaporated under reduced pressure to give a dark oil. Silica gel chromatography (98:1.8:0.2 CHCl3:CH3OH:NH4OH) of the residue gave a 60% yield of 2-methyl-1H-indol-5-ol (1.09 g) as a tan solid. C9H9NO: GC/MS: r.t.=2.88 min., m/z 146. 1H NMR (CD3OD): δ 7.03 (d, 1H, J=8.7 Hz), 6.77 (s, 1H), 6.53 (D, 1H, J=8.7 Hz), 5.92 (s, 1H), 2.32 (s, 3H) ppm.

Provenance & Evidence