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-Eintrag

ord-d5f7c158b4d64f998c99864b7e9f489c

Quelldatensatz

uspto-grants-2002_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06417213B2