Potassium Hydroxide → 7-Fluoro-4-trifluoromethoxy-1H-indole

Participants

Reaction Conditions

Reaction Steps

A mixture of 4 (28.9 g, 79.6 mmol) and KOH (35.7 g, 636.7 mmol) in degassed t-BuOH (300 mL) is heated at 70° C. overnight. LC/MS indicates the reaction is completed. The mixture is cooled to rt, and then partitioned between H2O and Et2O. The two layers are separated, and the aqueous layer was extracted with Et2O (2×). The combined organic layers are washed with H2O and brine, dried over MgSO4, filtered, and concentrated in vacuo. The crude material is purified on silica gel with heptane/EtOAc (100/0 to 60/40) as eluant to give 16 g (91%) of 5 as a yellow liquid. 1H NMR (CDCl3) δ 8.47 (br s, 1H), 7.35-7.20 (m, 1H), 6.95-6.80 (m, 2H), 6.68 (d, J=2.5 Hz, 1H); 19F NMR (CDCl3) δ −57.63 (s, 3F), −136.10 (d, J=8.5 Hz, 1F); MS 220 (M+1, 100%), 200.

Provenance & Evidence