N,N-Dimethylaniline → 2,6-dichloro-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 6-chloroindolin-2-one 1 (500 mg, 2.99 mmol) in toluene (25 mL) under inert atmosphere were added N,N-dimethylaniline (362 mg, 2.99 mmol) and POCl3 (918 g, 5.98 mmol) at RT; heated to 110° C. and stirred for 1 h. The reaction was monitored by TLC; after completion of the reaction, the reaction mixture was quenched with 10% aq. NaHCO3 solution (30 mL) and extracted with EtOAc (2×30 mL). The combined organic extracts were dried over Na2SO4, filtered and concentrated under reduced pressure to obtain the crude. This was purified by silica gel column chromatography using 5% EtOAc/Hexanes to afford compound 2 (350 mg, 63%) as an off-white solid. 1H NMR (400 MHz, CDCl3): δ 8.09 (br s, 1H), 7.41 (d, J=8.4 Hz, 1H), 7.28 (s, 1H), 7.09 (d, J=8.4 Hz, 1H), 6.39 (s, 1H); MS (ESI): m/z 184 (M−H+)

Provenance & Evidence