3-(4-Bromothiophenoxy)propionic acid → 6-Bromo-2,3-dihydro-4H-1-benzothiopyran-4-one

HRID 617694Notes

Reaction equation

HRID 617694 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([S:8][CH2:9][CH2:10][C:11]([OH:13])=O)=[CH:4][CH:3]=1>S(=O)(=O)(O)O>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:8][CH2:9][CH2:10][C:11](=[O:13])[C:6]=2[CH:7]=1

Participants

3

Reactant 1

HCID 167762423-(4-Bromothiophenoxy)propionic acid

Product 1

HCID 139537366-Bromo-2,3-dihydro-4H-1-benzothiopyran-4-oneYield 57.3%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

200 mL of concentrated sulfuric acid was added to 27.7 g (0.106 mol) of the title compound of Step A. The mixture was stirred at room temperature under nitrogen overnight, and was then poured over crushed ice. The mixture was filtered, and the solid was dissolved in methylene chloride. The resulting solution was dried (MgSO4), filtered, and evaporated to dryness to yield 14.77 g of the title compound of Step B as a solid melting at 50° C. (dec). 1H NMR (CDCl3): δ3.0 (m,2H), 3.2 (m,2H), 7.16-8.2 (3H).

Workup

  1. additionwas then poured
  2. customover crushed ice
  3. filtrationThe mixture was filtered
  4. dissolutionthe solid was dissolved in methylene chloride
  5. dry with materialThe resulting solution was dried (MgSO4)
  6. filtrationfiltered
  7. customevaporated to dryness

Sources & evidence

ORD record
ord-c0a96694de4947318c2af7fe7de6c114
Source dataset
uspto-grants-1999_09
Patent number
US05952266

Reaction notes

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