Water → 1,2-Benzoisothiazoline 1,1-dioxide

HRID 379616Notes

Reaction equation

HRID 379616 reaction equation
[S:1]1([C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:5](=O)[NH:4]1)(=[O:3])=[O:2].[H-].[Al+3].[Li+].[H-].[H-].[H-].O.S(=O)(=O)(O)O>O1CCCC1>[S:1]1(=[O:2])(=[O:3])[C:12]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[CH2:5][NH:4]1

Participants

6

Reactant 4

HCID 962WaterHCID 1118Sulfuric AcidHCID 5143SaccharinHCID 21226445Aluminium lithium hydride

Product 1

HCID 136381,2-Benzoisothiazoline 1,1-dioxideYield 52%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

25.3 g (138 mM [sic]) of saccharin were added in portions over the course of 90 min to 7.1 g (187 mM [sic]) of lithium aluminum hydride in 400 ml of absolute tetrahydrofuran with vigorous stirring under nitrogen; during this, the temperature was maintained at room temperature by cooling in ice. After stirring overnight, the mixture was cooled in an ice bath and, while stirring vigorously, water was cautiously added dropwise, followed by 10% strength sulfuric acid. After the precipitated hydroxides had been filtered off with suction, washing with THF, the filtrate was concentrated, the residue was partitioned between methylene chloride and water and, after acidifying with 10% strength sulfuric acid, the organic phase was washed thoroughly with sodium carbonate solution. The organic phase was dried with sodium sulfate and filtered and then concentrated. 12.0 g (52%) of product of adequate purity were isolated.

Workup

  1. temperatureby cooling in ice
  2. stirringAfter stirring overnight
  3. temperaturethe mixture was cooled in an ice bath
  4. stirringwhile stirring vigorously
  5. filtrationAfter the precipitated hydroxides had been filtered off with suction
  6. washwashing with THF
  7. concentrationthe filtrate was concentrated
  8. customthe residue was partitioned between methylene chloride and water
  9. washthe organic phase was washed thoroughly with sodium carbonate solution
  10. dry with materialThe organic phase was dried with sodium sulfate
  11. filtrationfiltered
  12. concentrationconcentrated

Sources & evidence

ORD record
ord-45bdf94d6e2542cd90e6fe959a9160c8
Source dataset
uspto-grants-2001_10
Patent number
US06300354B1

Reaction notes

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