Toluene → 2-cyclopropyl-5-fluoro-1H-indole

Participants

Reaction Conditions

Reaction Steps

A solution of 2-cyclopropylethynyl-4-fluoro-phenylamine (0.80 g, 4.5 mmol) in PhMe (16 mL) is treated with InBr3 (80 mg, 0.23 mmol) and stirred at 110° C. for 0.5 h. The mixture is then poured over brine (20 mL), and extracted with EtOAc (3×20 mL). The combined organic layer is dried (Na2SO4), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography eluting with 0%-25% EtOAc in heptane to afford 2-cyclopropyl-5-fluoro-1H-indole (610 mg, 78%). MS: 176 (M+H); 1H NMR (300 MHz, CDCl3): δ 7.88 (s, NH, 1H), 7.12 (m, 2H), 6.83 (m, 1H), 6.09 (s, 1H), 1.90 (m, 1H), 0.95 (m, 2H), 0.77 (m, 2H).

Provenance & Evidence