Phosphorus oxychloride → 2-Chloroimidazo[1,2-a]pyridine-3-sulfonyl chloride

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Reaction Steps

In 30 ml of phosphorus oxychloride is suspended 5.0 g of 2-chloroimidazo[1,2-a]pyridine-3-sulfonic acid and the suspension is refluxed for 5 hours. After cooling, the reaction mixture is poured in 250 ml of ice-water and extracted with dichloromethane. The dichloromethane layer is separated and dried over anhydrous sodium sulfate and the dichloromethane is distilled off under reduced pressure to give 4.6 g of the title compound as pale yellow crystals.

Provenance & Evidence