Borane;tetrahydrofuran → 5-(trifluoromethyl)-1H-indole

Participants

Reaction Steps

To a solution of 4 (6.75 g, 31.38 mmol) in dry THF (200 mL) at 0° C. under nitrogen atmosphere BH3.THF solution (82 mL, 1 M in THF) was added dropwise. The mixture was allowed to warm to room temperature and stirred for 1 h. The reaction was quenched with 6N ice-cold aq. HCl (30 mL), made alkaline (pH 7-8) with 2 N NaOH, saturated with NaCl, extracted with EtOAc, the extracts were dried (MgSO4), concentrated. Purification by chromatoghraphy on silica gel using CH2Cl2 as eluent afforded (3.95 g, 68% yield) as an off white solid. 1H NMR (300 MHz, MeOH-d4): δ 7.87 (m, 1H), 7.51 (dd, 8.5, 0.8 Hz, 1H), 7.47 (d, 8.5 Hz, 1H), 7.37 (d, 3.2 Hz, 1H), 7.34 (dd, 8.5, 1.6 Hz, 1H), 6.57 (dd, 3.2, 0.8 Hz, 1H). MS m/z: 184 (M−1).

Provenance & Evidence