Triethylsilane → 4-Chloroindoline

Participants

Reaction Steps

A solution of 4-chloroindole (3.15 g) and triethylsilane (8.30 ml) in trifluoroacetic acid (32 ml) was stirred at 50° C. for 30 minutes. The solvent was evaporated under reduced pressure, and the residue was basified with a saturated aqueous sodium hydrogen carbonate solution. The mixture was extracted with ethyl acetate twice, and the combined organic layer was dried over magnesium sulfate. The insoluble materials were filtered off, and the filtrate was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0-80:20) to give the titled compound (2.89 g) as colorless oil. APCI-Mass m/Z 154/156 (M+H). 1H-NMR (DMSO-d6) δ 2.94 (t, J=8.7 Hz, 2H), 3.46 (t, J=8.7 Hz, 2H), 5.83 (s, 1H), 6.40 (d, J=7.7 Hz, 1H), 6.50 (d, J=8.0 Hz, 1H), 6.90 (t, J=7.9 Hz, 1H).

Provenance & Evidence