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

HRID 1819974Notes

Reaction equation

HRID 1819974 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([NH2:8])=[C:4]([NH2:9])[CH:3]=1.[S:10](Cl)(Cl)=O.S(=O)(=O)(O)O>>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]2=[N:8][S:10][N:9]=[C:4]2[CH:3]=1

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 72634-Chloro-1,2-diaminobenzeneHCID 24386Thionyl Chloride

Product 1

HCID 2841235-Chloro-2,1,3-benzothiadiazole

Procedure

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%).

Workup

  1. customA mixture was prepared
  2. temperaturewas refluxed for one hour
  3. temperatureThis mixture was cooled
  4. additionpoured onto ice
  5. filtrationa resultant precipitate was filtered
  6. customcollected
  7. washThis precipitate was washed with water till the waste water
  8. customthoroughly dried

Sources & evidence

ORD record
ord-33b979f09ee443f1b1deb1414f8522a7
Source dataset
uspto-grants-2009_10
Patent number
US07601873B2

Reaction notes

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