Hydrochloric Acid → 5,6-dichloropyridine-3-sulfonyl Chloride

Participants

Reaction Steps

With cooling with ice, an aqueous solution (2.5 ml) of sodium nitrite (1.1 g, 16.0 mmol) was added to a hydrochloric acid solution (15 ml) of 5,6-dichloropyridine-3-amine (2.0 g, 12.3 mmol), stirred for 30 minutes, and the reaction solution was filtered. The filtrate was added to a mixed hydrochloric acid (35 ml)/water (8 ml) solution of sodium sulfite (3.87 g, 30.7 mmol) and copper sulfate (0.29 g, 1.84 mmol) along with an aqueous solution (8 ml) of sodium sulfite (3.87 g, 30.7 mmol) thereto, with cooling with ice, and stirred for 30 minutes. The reaction solution was extracted with chloroform, the organic layer was washed with saturated saline water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 5,6-dichloropyridine-3-sulfonyl chloride (2.41 g, yield: 80%) as a brown oil.

Provenance & Evidence