Sulfuric Acid → 5-Bromo-benzo[2,1,3]thiadiazole

Participants

Reaction Steps

A mixture was prepared by mixing 4.0 g (21 mmol) of 4-bromo-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 resulting precipitate was filtered and collected. This precipitate was washed with water till the waste water became neutral and then thoroughly dried to yield 4.5 g of 5-bromo-2,1,3-benzothiadiazole as a crude product (melting point, 48 to 50° C.; yield, 96.5%). This crude product was vacuum-distilled to yield a pure product of 5-bromo-2,1,3-benzothiadiazole (melting point, 50° C.; yield, 86%).

Provenance & Evidence