Boron tribromide → 2-bromomethyl-4-isopropyl-6-hydroxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

HRID 1289866Notes

Reaction equation

HRID 1289866 reaction equation
[Br:1][CH2:2][N:3]1[C:7](=[O:8])[C:6]2[C:9]([CH:15]([CH3:17])[CH3:16])=[CH:10][C:11]([O:13]C)=[CH:12][C:5]=2[S:4]1(=[O:19])=[O:18].B(Br)(Br)Br>>[Br:1][CH2:2][N:3]1[C:7](=[O:8])[C:6]2[C:9]([CH:15]([CH3:16])[CH3:17])=[CH:10][C:11]([OH:13])=[CH:12][C:5]=2[S:4]1(=[O:18])=[O:19]

Participants

3

Reactant 2

HCID 25134Boron tribromideHCID 108825772-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

Product 1

HCID 189225922-bromomethyl-4-isopropyl-6-hydroxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxideYield 124.5%

Procedure

A mixture of 2-bromomethyl-4-isopropyl-6-methoxy-l,-2-benzisothiazol-3(2H)-one 1,1-dioxide (44 g, 126.4 mmol) and BBr3 (1.0M in methylene chloride, 164.4 mmol) was allowed to reflux for 48 hours and then poured into ice/water. The mixture was filtered, the aqueous layer was extracted with ethyl acetate, and the mixture of the combined organic layer and the residue (from above filtration) was dried over sodium sulfate and concentrated in vacuo. The solid residue was recrystallized from toluene/cyclohexane (7:2) to afford 52.6 g (96 %) of 2-bromomethyl-4-isopropyl-6-hydroxy-1,2-benzisothiazol-3 (2H)-one 1,1-dioxide as solid, m.p. 167°-169° C.

Workup

  1. temperatureto reflux for 48 hours
  2. filtrationThe mixture was filtered
  3. extractionthe aqueous layer was extracted with ethyl acetate
  4. additionthe mixture of the combined organic layer
  5. filtrationthe residue (from above filtration)
  6. dry with materialwas dried over sodium sulfate
  7. concentrationconcentrated in vacuo
  8. customThe solid residue was recrystallized from toluene/cyclohexane (7:2)

Sources & evidence

ORD record
ord-182205af93b4415996f800b2ee93aa71
Source dataset
uspto-grants-1998_05
Patent number
US05750550

Reaction notes

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