3-(4-Fluorophenyl)-2-methylpropanoic acid → 6-Fluoro-2-methylindan-1-one

HRID 47634Notes

Reaction equation

HRID 47634 reaction equation
[F:1][C:2]1[CH:13]=[CH:12][C:5]([CH2:6][CH:7]([CH3:11])[C:8]([OH:10])=O)=[CH:4][CH:3]=1>O>[F:1][C:2]1[CH:3]=[C:4]2[C:5]([CH2:6][CH:7]([CH3:11])[C:8]2=[O:10])=[CH:12][CH:13]=1

Participants

3

Reactant 1

HCID 154877913-(4-Fluorophenyl)-2-methylpropanoic acid

Product 1

HCID 114465226-Fluoro-2-methylindan-1-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
95 °C

Procedure

To 932 g polyphosphoric acid at 70° C. (steam bath) is added p-fluoro-α-methylhydrocinnamic acid (93.2 g, 0.5 mol) slowly with stirring. The temperature is gradually raised to 95° C., and the mixture is kept at this temperature for 1 hour. The mixture is allowed to cool and is added to 2 l. of water. The aqueous suspension is extracted with ether. The extract is washed twice with saturated sodium chloride solution, 5% Na2CO3 solution, and water, and is dried, and is concentrated on 200 g silica-gel; the slurry is added to a five pound silica-gel column packed with 5% ether-petroleum ether. The column is eluted with 5-10% ether-petroleum ether, to give 6-fluoro-2-methylindanone. Elution is followed by TLC.

Workup

  1. temperatureto cool
  2. additionis added to 2 l
  3. extractionThe aqueous suspension is extracted with ether
  4. washThe extract is washed twice with saturated sodium chloride solution, 5% Na2CO3 solution, and water
  5. customis dried
  6. concentrationis concentrated on 200 g silica-gel
  7. additionthe slurry is added to a five pound silica-gel column
  8. washThe column is eluted with 5-10% ether-petroleum ether

Sources & evidence

ORD record
ord-728fb8f0790242ca9cfbccda3337f393
Source dataset
uspto-grants-2004_03
Patent number
US06699894B1

Reaction notes

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