Dimethylformamide → HCID 11206654, compound

Participants

Reaction Steps

Under nitrogen, 27 ml (292 mmol) of phosphorus oxychloride were added dropwise at 0° C. to 28 ml (366 mmol) of N,N-dimethylformamide in 190 ml of dichloromethane. The mixture was stirred for 2 h at ambient temperature. It was cooled to 0° C. and 24.5 g (146 mmol) of 6-chloro-1,3-dihydro-2H-indol-2-one were added in small portions. The mixture was stirred for 4 h at ambient temperature. It was cooled to 0° C. and 12.7 ml (146 mmol) of oxalyl chloride were added. Next, it was stirred for 12 h at ambient temperature. The mixture was cooled and 250 ml of water were added. The organic phase was decanted and washed with water (3 times). A solid precipitated from the organic phase. It was recovered by filtration and dried under reduced pressure in the presence of phosphorus pentoxide. The aqueous phases were combined and stirred for around 7 h. A solid precipitated from the aqueous phase. It was recovered by filtration and it was also dried under reduced pressure in the presence of phosphorus pentoxide. The two precipitates were combined and 16 g of 2,6-dichloro-1H-indole-3-carbaldehyde were obtained in the form of a white/beige solid.

Provenance & Evidence