Dimethylformamide → 2-chloro-1H-indole-3-carbaldehyde

Participants

Reaction Steps

To DMF (30 mL) with stirring at 0° C. was added dropwise phosphorus oxychloride (10 mL, 107 mmole) over 5 minutes. The reaction was stirred for an additional 15 minutes, then oxindole (6.0 g, 45 mmole) was added portionwise over 5 min. The reaction was allowed to warm to RT and stirred for 18 h then was carefully poured into ice water (350 mL). The solution was stirred for 6 h after which time a suspension formed. The solids were filtered off, washed with cold water, pressed dry and dried under vacuum to give the title compound (6.83 g, 84%) as a yellowish solid: 1H NMR (400 MHz, d6-DMSO) δ 10.0 (s, 1 H), 8.05 (dd, 1 H), 7.43 (dd, 1 H), 7.23–7.31 (m, 2 H); MS (ES) m/e 179.0 (M+H)+.

Provenance & Evidence