Dimethylformamide → 5-chloro-1H-indole-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To stirred dimethylformamide (20 mL) at 0° C. was added dropwise phosphorus oxychloride (4.6 mL, 49 mmol). The mixture was stirred for 10 min and a solution of 5-chloroindole (5.0 g, 33 mmol) in dimethylformamide (5 mL) was added dropwise. The mixture was heated to 40° C. for 45 min, cooled to room temperature and then treated with a solution of sodium hydroxide (5.9 g, 148 mmol) in water (20 mL). The mixture was heated to 50° C. for 10 min, cooled to room temperature, poured onto crushed ice (100 mL) and filtered. The filter cake was recrystallised (methanol) to give the product as a white solid (3.5 g, 59%): mp 215-216° C.; Found: C, 60.13; H, 3.40; N, 7.75%. C9H6ClNO requires: C, 60.19; H, 3.37; N, 7.79%.

Provenance & Evidence