Water → 2,3-dihydro-8-hydroxy-4H-1-Benzopyran-4-one

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%.

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

ORD record

ord-d1461a58bfe74c91b88ad145aca151eb

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06248766B1