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

Participants

Reaction Conditions

Reaction Steps

5-Amino-2,3-dichloropyridine (20.0 g, 123 mmol) was dissolved in 600 ml conc. HCl, and the solution cooled to 5° C. Sodium nitrate (8.5 g, 123 mmol) in 75 ml water was added dropwise, below the surface of the reaction, at such a rate that the temperature was maintained below 10° C. The reaction was stirred 15 minutes after the addition was complete. This mixture was then added rapidly to a solution of 600 ml acetic acid saturated with sulfur dioxide and containing also cupric chloride dihydrate (1.5 g), the solution cooled to 5° C. The reaction PG,38 was stirred at 5° C. for 20 minutes, then room temperature for 30 minutes and finally poured into 12 liters ice/water. The resulting solids were filtered off, washed with water, and air-dried. Yield: 17.27 g, 57 percent, m.p. 48°-51° C.

Provenance & Evidence