Acetic Acid → Indole

Participants

Reaction Steps

Ketone 2 (3.65 gr, 17 mmol) and 4-trifluoromethoxy phenylhydrazine hydrochloride (4.66 gr, 20.4 mmol) were stirred at reflux in acetic acid (0.25M) for 1 h under nitrogen atmosphere. The reaction was cooled to room temperature the acetic acid was removed under reduced pressure and the residue was diluted with ether and washed with water (1×) and brine (1×). The ether layer was dried with magnesium sulfate, filter and evaporated to afford 3 as a yellow oil after column chromatography (hexanes/ethyl acetate, 4:1); 1H-NMR (CDCl3, 500 MHz) δ 7.79 (br s, 1H), 7.25 (d, 1H), 7.17 (s, 1H), 7.14 (t, 1H), 7.03 (dd, 1H), 6.58 (dd, 1H), 6.50 (dd, 1H), 6.44 (t, 1H), 4.95 (br s, 1H), 2.33 (s, 1H).

Provenance & Evidence