Hydrochloric Acid → 7-(Trifluoromethyl)-1H-indole

Temperature

-20 °C

To a stirred mixture of 7-trifluoromethyl-1H-indole-2,3-dione (116 mg) in THF (5.00 mL) was added boron trifluoride etherate (0.205 mL, 1.62 mmol) followed by sodium borohydride (71.4 mg, 1.88 mmol). The resulting mixture was stirred at −20° C. for 2 hrs, then water (1 mL) was added and the mixture was stirred at 0° C. for 10 min. The solution was acidified to pH=1 with 2N HCl, warmed to r.t. and stirred at rt. for 20 min prior to extraction with EtOAc. The extracts were dried over magnesium sulphate, concentrated in vacuo and the residue purified by chromatography over silica gel eluting with hexane to give 7-trifluoromethyl-1H-indole. 1H NMR (400 MHz, CDCl3) δ ppm 6.63-6.68 (1 H, m), 7.20 (1 H, t, J=7.71 Hz), 7.30-7.35 (1 H, m), 7.47 (1 H, d, J=7.33 Hz), 7.83 (1 H, d, J=8.08 Hz), and 8.56 (1 H, br. s.).

1. stirringthe mixture was stirred at 0° C. for 10 min
2. temperaturewarmed to r.t.
3. stirringstirred at rt
4. waitfor 20 min
5. extractionto extraction with EtOAc
6. dry with materialThe extracts were dried over magnesium sulphate
7. concentrationconcentrated in vacuo
8. customthe residue purified by chromatography over silica gel eluting with hexane

ORD record

ord-df83c56af90f4795b3fd5c9a21a220aa

Source dataset

uspto-grants-2010_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07651687B2