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

HRID 377357Notes

Reaction equation

HRID 377357 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 polyphosphoric acid (932 g) at 70° C. on the steam bath is added p-fluoro-α-methylhydrocinnamic acid (93.2 g, 0.5 mole) slowly with stirring. The temperature is gradually raised to 95° C., and the mixture is kept at that temperature for 1 hour. The mixture is allowed to cool and added to 2 liters of water. The aqueous layer is extracted with ether, the ether solution washed twice with saturated sodium chloride solution, 5% Na2CO3 solution, water, and then dried. The ether filtrate is concentrated with 200 g silica-gel, and added to a five pound silica-gel column packed with 5% ether-petroleum ether. The column is eluted with 5-10% ether-petroleum ether and followed by TLC to give 6-fluoro-2-methylindanone.

Workup

  1. temperatureto cool
  2. extractionThe aqueous layer is extracted with ether
  3. washthe ether solution washed twice with saturated sodium chloride solution, 5% Na2CO3 solution, water
  4. customdried
  5. concentrationThe ether filtrate is concentrated with 200 g silica-gel
  6. additionadded to a five pound silica-gel column
  7. washThe column is eluted with 5-10% ether-petroleum ether

Sources & evidence

ORD record
ord-5f79ecaf29114182b72fd7efa97f84a6
Source dataset
uspto-grants-2000_02
Patent number
US06025394

Reaction notes

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