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

Temperatur

-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 r.t. 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 r.t. for 20 min
4. extractionto extraction with EtOAc
5. dry with materialThe extracts were dried over magnesium sulphate
6. concentrationconcentrated in vacuo
7. customthe residue purified by chromatography over silica gel eluting with hexane

ORD-Eintrag

ord-ac421b94dde243209ef42c6a1ae42d70

Quelldatensatz

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07943767B2