p-Toluenesulfonic acid monohydrate → 5-Bromo-1-benzothiophene

HRID 2390958Notes

Reaction equation

HRID 2390958 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:9][CH2:8][CH:7](O)[C:6]=2[CH:11]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>CC(C)=O>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:9][CH:8]=[CH:7][C:6]=2[CH:11]=1

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 57615036HCID 57615036, compound

Product 1

HCID 27765785-Bromo-1-benzothiopheneYield 96.9%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To acetone (600 mL) solution of 300 g of 5-bromo-2,3-dihydro-1-benzothiophen-3-ol was added 12.4 g of p-toluenesulfonic acid monohydrate, which was then refluxed for 2 hours. To the reaction solution was added 15.0 g of activated carbon, which was then stirred. Insoluble matter was filtered off and washed with 300 mL of acetone. The filtrate and washings were combined, to which was dropwise added 2700 mL of water at 5 to 15° C. The precipitate was collected by filtration to provide 268 g of 5-bromo-1-benzothiophene as pale purple solid form.

Workup

  1. temperaturewas then refluxed for 2 hours
  2. additionTo the reaction solution was added 15.0 g of activated carbon, which
  3. filtrationInsoluble matter was filtered off
  4. washwashed with 300 mL of acetone
  5. customat 5 to 15° C
  6. filtrationThe precipitate was collected by filtration

Sources & evidence

ORD record
ord-a64c1fb1562e4e2184a5ef6478f9c063
Source dataset
uspto-grants-2012_09
Patent number
US08273902B2

Reaction notes

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