Sulfamide → 1-(Propan-2-yl)-1,3-dihydro-2lambda6,1,3-benzothiadiazole-2,2-dione

HRID 1819669Notes

Reaction equation

HRID 1819669 reaction equation
[CH:1]([NH:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=1[NH2:11])([CH3:3])[CH3:2].[S:12](N)(N)(=[O:14])=[O:13]>N1C=CC=CC=1>[CH:1]([N:4]1[C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[NH:11][S:12]1(=[O:14])=[O:13])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 82267SulfamideHCID 105587871-N-(propan-2-yl)benzene-1,2-diamine

Product 1

HCID 596406791-(Propan-2-yl)-1,3-dihydro-2lambda6,1,3-benzothiadiazole-2,2-dioneYield 81.1%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a solution of N-isopropyl-1,2-phenylenediamine (7.52 g, 50.0 mmol) in pyridine (200 mL) was added sulfamide (7.21 g, 75 mmol, 1.5 equiv.) and the mixture was refluxed for 1 hour. After cooling, pyridine was removed under reduced pressure. Residual pyridine was removed by azeotrope evaporation using toluene. The black residue was dissolved in chloroform (150 mL) and the solution was washed with an aqueous hydrochloric acid solution (2 N, 2×50 mL), water, brine, dried (anhydrous sodium sulfate), and concentrated to give a crude black oil, which was purified by Isco CombiFlash Companion column chromatography (silica gel, 0-40% ethyl acetate/hexane, with 1% formic acid additive) to give 8.61 g (81%) of 1-isopropyl-1,3-dihydro-2,1,3-benzothiadiazole 2,2-dioxide as a viscous brown liquid.

Workup

  1. temperaturethe mixture was refluxed for 1 hour
  2. temperatureAfter cooling
  3. custompyridine was removed under reduced pressure
  4. customResidual pyridine was removed by azeotrope evaporation
  5. dissolutionThe black residue was dissolved in chloroform (150 mL)
  6. washthe solution was washed with an aqueous hydrochloric acid solution (2 N, 2×50 mL), water, brine
  7. dry with materialdried (anhydrous sodium sulfate)
  8. concentrationconcentrated
  9. customto give a crude black oil, which
  10. customwas purified by Isco CombiFlash Companion column chromatography (silica gel, 0-40% ethyl acetate/hexane, with 1% formic acid additive)

Sources & evidence

ORD record
ord-574a2bb7e1a443ad884b4077ef76c09a
Source dataset
uspto-grants-2009_10
Patent number
US07601744B2

Reaction notes

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