Chlorosulfonic acid → Benzo[c]isothiazole-7-sulfonyl chloride

HRID 2202364Notes

Reaction equation

HRID 2202364 reaction equation
[N:1]1[S:2][CH:3]=[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=12.[Cl:10][S:11](O)(=[O:13])=[O:12]>>[N:1]1[S:2][CH:3]=[C:4]2[CH:9]=[CH:8][CH:7]=[C:6]([S:11]([Cl:10])(=[O:13])=[O:12])[C:5]=12

Participants

3

Reactant 2

HCID 24638Chlorosulfonic acidHCID 638008Benzo[c]isothiazole

Product 1

HCID 90418910Benzo[c]isothiazole-7-sulfonyl chlorideYield 15.6%

Procedure

Benzo[c]isothiazole 24B (1 g, 7.45 mmol) was added dropwise to chlorosulfonic acid (5.5 mmol) at 0° C. After the addition was complete, the mixture was stirred at room temperature for 0.5 h and then heated at 105° C. and stirred overnight. The resulting mixture was cooled to −10° C. and quenched by pouring on crushed ice slowly. The resulting mixture was extracted with EtOAc (100 mL×2). The combined organic phase was washed with brine, dried over anhy. Na2SO4 and concentrated in vacuo. Column chromatography (15% PE/EtOAc) afforded 200 mg of title compound. 1H NMR (CHLOROFORM-d) δ: 9.68 (s, 1H), 8.66 (d, J=1.9 Hz, 1H), 8.10 (d, J=9.4 Hz, 1H), 7.99 (dd, J=9.4, 2.1 Hz, 1H).

Workup

  1. additionAfter the addition
  2. temperatureheated at 105° C.
  3. stirringstirred overnight
  4. temperatureThe resulting mixture was cooled to −10° C.
  5. customquenched
  6. additionby pouring
  7. customon crushed ice slowly
  8. extractionThe resulting mixture was extracted with EtOAc (100 mL×2)
  9. washThe combined organic phase was washed with brine
  10. customdried over anhy
  11. concentrationNa2SO4 and concentrated in vacuo

Sources & evidence

ORD record
ord-5831bec709f1419c865b2af1fa412c47
Source dataset
uspto-grants-2016_06
Patent number
US09365545B2

Reaction notes

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