Water → 2,7-Difluoro-3-methyl-9H-fluorenone

HRID 465487Notes

Reaction equation

HRID 465487 reaction equation
[CH3:1][C:2]1[C:3]([C:12]2[CH:17]=[CH:16][C:15]([F:18])=[C:14]([CH3:19])[CH:13]=2)=[C:4]([CH:8]=[C:9]([F:11])[CH:10]=1)C(O)=O.[OH2:20]>>[F:18][CH:15]1[C:14]([CH3:19])=[CH:13][C:12]2[C:3]3[C:2](=[CH:10][C:9]([F:11])=[CH:8][CH:4]=3)[CH2:1][C:17]=2[C:16]1=[O:20]

Participants

3

Reactant 2

HCID 962WaterHCID 19874639Methyl 2-(3-methyl-4-fluorophenyl)-5-fluorobenzoic acid

Product 1

HCID 679031352,7-Difluoro-3-methyl-9H-fluorenoneYield 33%

Conditions

Temperature
180 °C

Procedure

A stirred mixture of methyl 2-(3-methyl-4-fluorophenyl)-5-fluorobenzoic acid (6.5 g, 26.2 mmol) and polyphosphoric acid (30 g) was heated at 180° C. for 2 h. After the mixture had cooled to 80° C., it was poured into water (200 mL), and extracted with ethyl acetate. The combined extracts were washed with brine, dried over MgSO4, treated with charcoal, and concentrated. Chromatography on silica gel using 20% toluene in hexane provided 2 g (33%) of the desired ketone.

Workup

  1. temperatureAfter the mixture had cooled to 80° C.
  2. extractionextracted with ethyl acetate
  3. washThe combined extracts were washed with brine
  4. dry with materialdried over MgSO4
  5. additiontreated with charcoal
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-09782fc3af5c4933b3044ec73d1e2e59
Source dataset
uspto-grants-1992_10
Patent number
US05153211

Reaction notes

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