反应详情

4,7-Dihydroxy-5-methylcoumarin (200 mg; 1.04 mmole) was dissolved in methanol (5 mL). A 60% aqueous dimethoxyacetaldehyde solution (792 μL; 8.7 mmole) was added and the reaction mixture was refluxed for 5 hours. By cooling to room temperature a white precipitate was precipitated, which was filtered off and washed with methanol. Obtained was the title compound in a 92% yield and of sufficient purity to be used in the next synthesis step:

1. temperaturethe reaction mixture was refluxed for 5 hours
2. customwas precipitated
3. filtrationwhich was filtered off
4. washwashed with methanol
5. customObtained