Potassium Carbonate → 1-[5-(Benzyloxy)-3-methyl-1-benzofuran-2-yl]-2-methylpropan-1-one

To a solution (200 mL) of 1-[5-(benzyloxy)-2-hydroxyphenyl]ethanone (16.1 g) synthesized in Example A82(1) in N,N-dimethylformamide were added at room temperature potassium carbonate (27.6 g) and 1-bromo-3-methylbutan-2-one (14.3 g) synthesized in Example A75(1), and the mixture was stirred for 15 hr. The reaction mixture was filtered through celite, water (200 mL) was added and the mixture was extracted with diethyl ether (100 mL×2). The extract was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was dissolved in N,N-dimethylformamide (100 mL), and DBU (9.9 mL) was added at room temperature. The reaction mixture was stirred at 100° C. for 1 hr. The reaction mixture was allowed to cool to room temperature, 1N hydrochloric acid (150 mL) was added, and the mixture was extracted with diethyl ether (100 mL×2). The extract was washed with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was recrystallized from ethanol-diisopropyl ether to give the title object compound (11.7 g, 57%) as pale-yellow crystals.

1. filtrationThe reaction mixture was filtered through celite, water (200 mL)
2. additionwas added
3. extractionthe mixture was extracted with diethyl ether (100 mL×2)
4. washThe extract was washed with saturated brine
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. dissolutionThe residue was dissolved in N,N-dimethylformamide (100 mL)
8. additionDBU (9.9 mL) was added at room temperature
9. stirringThe reaction mixture was stirred at 100° C. for 1 hr
10. addition1N hydrochloric acid (150 mL) was added
11. extractionthe mixture was extracted with diethyl ether (100 mL×2)
12. washThe extract was washed with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine
13. dry with materialdried over magnesium sulfate
14. concentrationconcentrated under reduced pressure
15. customThe residue was recrystallized from ethanol-diisopropyl ether

ORD record

ord-d68bf00a028b419faf7ff35fc934c553

Source dataset

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08436043B2