反应详情

2-(4-fluorobenzoyl)-1-benzofuran-5-carbaldehyde (500 mg, 1.86 mmol) and ethylene glycol (2.31 g, 37.2 mmol) were suspended in toluene (20 mL) followed by the addition of (1S)-(+)-10-camphorsulfonic acid (30 mg). This suspension was heated under reflux for 2 hours. After allowing the reaction mixture to cool on standing, saturated aqueous sodium bicarbonate solution was poured thereinto followed by extraction with ethyl acetate. The organic layer was separated followed by washing with sat. NaCl and drying over anhydrous magnesium sulfate. The organic layer was filtered using a glass filter and the filtrate was filtered with a glass filter coated with NH-silica gel. This filtrate was concentrated under a reduced pressure to obtain (5-[1,3]-dioxolan-2-yl-benzofuran-2-yl)-(4-fluoro-phenyl)-methanone (377 mg, 65%).

1. temperatureThis suspension was heated
2. temperatureunder reflux for 2 hours
3. temperatureto cool
4. extractionthereinto followed by extraction with ethyl acetate
5. customThe organic layer was separated
6. washby washing with sat. NaCl
7. dry with materialdrying over anhydrous magnesium sulfate
8. filtrationThe organic layer was filtered
9. filtrationfilter
10. filtrationthe filtrate was filtered with a glass
11. filtrationfilter
12. concentrationThis filtrate was concentrated under a reduced pressure