Water → 8-Hydroxy-2,3-dihydro-4H-1-benzopyran-4-one

HRID 1067409Notes

Reaction equation

HRID 1067409 reaction equation
C[O:2][C:3]1[C:12]2[O:11][CH2:10][CH2:9][C:8](=[O:13])[C:7]=2[CH:6]=[CH:5][CH:4]=1.[Cl-].[Al+3].[Cl-].[Cl-].O>C1(C)C(C)=CC=CC=1>[OH:2][C:3]1[C:12]2[O:11][CH2:10][CH2:9][C:8](=[O:13])[C:7]=2[CH:6]=[CH:5][CH:4]=1

Participants

5

Reactant 3

HCID 962WaterHCID 6451240Aluminum(III) ChlorideHCID 122518658-Methoxy-4-Chromanone

Product 1

HCID 111266018-Hydroxy-2,3-dihydro-4H-1-benzopyran-4-oneYield 56.6%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Conditions

Temperature
100 °C

Procedure

2,3-Dihydro-8-methoxy-4H-1-benzopyran-4-one (7.59 g, 42.4 mmol) was dissolved in xylene (80 mL) followed by addition of anhydrous aluminum chloride (11.4 g, 85.5 mmol), and the mixture was stirred at 100° C. for 2 hours. After cooling, the reaction mixture was poured into iced water and extracted with ethyl acetate. The organic layer was washed with 1N-hydrochloric acid and saturated aqueous sodium chloride solution, dried over MgSO4, and filtered. The filtrate was concentrated under reduced pressure and the residue was crystallized from methanol-ethyl acetate-diethyl ether to provide 3.94 g of the title compound. Yield 56%.

Workup

  1. temperatureAfter cooling
  2. extractionextracted with ethyl acetate
  3. washThe organic layer was washed with 1N-hydrochloric acid and saturated aqueous sodium chloride solution
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationThe filtrate was concentrated under reduced pressure
  7. customthe residue was crystallized from methanol-ethyl acetate-diethyl ether

Sources & evidence

ORD record
ord-d1461a58bfe74c91b88ad145aca151eb
Source dataset
uspto-grants-2001_06
Patent number
US06248766B1

Reaction notes

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