1H-Indole, 4-broMo-7-(trifluoroMethyl)- synthesis

Yield:1360959-14-3 25%

Reaction Conditions:

Stage #1: 4-bromo-2-nitro-1-(trifluoromethyl)benzene;vinyl magnesium bromide in tetrahydrofuran at -78; for 1.5 h;
Stage #2: with ammonium chloride in tetrahydrofuran;

Steps:

B-12.1 Step 1 4-Bromo-7-trifluoromethylindole

To a solution of 4-bromo-2-nitro-1-trifluoromethyl-benzene 11.4g, 0.04mol) in 200mL THF was added vinyl magnesium bromide (160mL, 0.16mol) at -78°C and the mixture was stirred for 1.5 hrs before quenching with a saturated solution of NH₄CI and extracting with EtOAc. The organic phase was dried over Na₂S0 and the solvent removed in vacuo. The crude product was purified by silica gel column chromatography to give the title compound (2g, 25%). ¹H NMR (CDCI₃ 400 MHz), δ 8.6 (br, 1 H), 7.28-7.38 (m, 3H), 6.70 (m, 1 H).

References:

WO2013/117522,2013,A1 Location in patent:Page/Page column 47