Dimethyl Sulfate → 2-Methyl-1,2-benzoisothiazolin-3-one

HRID 335503Notes

Reaction equation

HRID 335503 reaction equation
[Li].[S:2]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[C:4](=[O:11])[NH:3]1.S(OC)(O[CH3:16])(=O)=O.COC1C2C=CC=CC=2SN=1>CC(=O)CC>[CH3:16][N:3]1[C:4](=[O:11])[C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[S:2]1

Participants

5

Reactant 3

HCID 6497Dimethyl SulfateHCID 387363-Methoxy-1,2-benzisothiazoleHCID 70348857111337-53-22×

Product 1

HCID 3512362-Methyl-1,2-benzoisothiazolin-3-oneYield 77%

Reagents, catalysts & solvents 1

HCID 6569Methyl Ethyl KetoneSolvent

Procedure

To a stirred suspension of 1,2-benzisothiazolin-3-one lithium salt (10.0 g, 63.7 mmol) in butanone (30 ml) was added dropwise dimethyl sulfate (8.4 g, 6.4 ml, 66.9 mmol). The resulting slurry was stirred at room temperature for 90 hours. HPLC analysis showed greater than 96% alkylation of 1,2-benzisothiazolin-3-one lithium salt. The solvent was evaporated and the crude product distilled under reduced pressure to give a combined 77% yield of N-methyl-1,2-benzisothiazolin-3-one and 3-methoxy-1,2-benzisothiazole, with N-methyl-1,2-benzisothiazolin-3-one isolated in 94% purity. The ratio of N-alkylated material to O-alkylated material was 90:10.

Workup

  1. customThe solvent was evaporated
  2. distillationthe crude product distilled under reduced pressure

Sources & evidence

ORD record
ord-e113474e9b3d40ae97de06c83887d638
Source dataset
uspto-grants-2014_11
Patent number
US08884024B1

Reaction notes

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