3-(4-Fluorophenoxy)propionic acid → 6-fluoro-2,3-dihydro-4H-1-benzopyran-4-one

HRID 1732111Notes

Reaction equation

HRID 1732111 reaction equation
[F:1][C:2]1[CH:13]=[CH:12][C:5]([O:6][CH2:7][CH2:8][C:9]([OH:11])=O)=[CH:4][CH:3]=1>S(=O)(=O)(O)O>[F:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:12][CH:13]=1)[O:6][CH2:7][CH2:8][C:9]2=[O:11]

Participants

3

Reactant 1

HCID 740993-(4-Fluorophenoxy)propionic acid

Product 1

HCID 27332626-fluoro-2,3-dihydro-4H-1-benzopyran-4-oneYield 76%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

A mixture of 30.0 g (163.0 mmol) of 3-(4-fluorophenoxy)propionic acid and 180 ml of concentrated sulfuric acid was stirred for 1 hour at room temperature and then the reaction mixture was poured into 700 g of ice to deposit immediately a white crystal. The white crystal was collected by filtration, washed with water and dried in air, and the resultant was recrystallized from ethanol to give 20.55 g of 6-fluoro-4-chromanone as a white crystal (yield: 76%).

Workup

  1. filtrationThe white crystal was collected by filtration
  2. washwashed with water
  3. customdried in air
  4. customthe resultant was recrystallized from ethanol

Sources & evidence

ORD record
ord-f7c19620fad74311a2eb5d8b4b6ac623
Source dataset
uspto-grants-1986_11
Patent number
US04625042

Reaction notes

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