Sulfuric Acid → 5-Chloro-2,1,3-benzothiadiazole

Participants

Reaction Steps

A mixture was prepared by mixing 4.0 g (28 mmol) of 4-chloro-o-phenylenediamine, 14 mL of thionyl chloride and 0.62 mL of concentrated sulfuric acid and was refluxed for one hour. This mixture was cooled and then poured onto ice, and a resultant precipitate was filtered and collected. This precipitate was washed with water till the waste water became neutral and then thoroughly dried to yield 4.6 g of 5-chloro-2,1,3-benzothiadiazole as a crude product (melting point, 50 to 54° C.; yield, 96%). This crude product was vacuum-distilled to yield a pure product of 5-chloro-2,1,3-benzothiadiazole (melting point, 54° C.; yield, 85%).

Provenance & Evidence