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

HRID 1460366Notes

Reaction equation

HRID 1460366 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-6f07452d71e54036be21ab2e942164f0
Source dataset
uspto-grants-1991_12
Patent number
US05070100

Reaction notes

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