反应详情

温度

210 °C

A mixture of acetic acid 3-(2,4-dimethoxyphenyl)-7-hydroxy-4-methyl-2-oxo-2H-chromen-7-yl ester, prepared as in Example 1 (0.177 g, 0.5 mmol, 1 eq) and dry pyridine hydrochloride (0.9 g, 8.8 mmol, 16 eq) was stirred and heated in an oil bath to a melt, at 210° C. under a closed nitrogen atmosphere in a loosely stoppered round bottom flask for 1 hour. After cooling to room temperature the reaction mixture was triturated with water and the aqueous solution was extracted several times with ethyl acetate until the latter was colorless. Combined organic extracts were washed with brine, dried (anhydrous sodium sulphate), filtered and evaporated to yield the title compound as a pinkish crystalline solid.

1. temperatureAfter cooling to room temperature the reaction mixture
2. customwas triturated with water
3. extractionthe aqueous solution was extracted several times with ethyl acetate until the latter
4. washCombined organic extracts were washed with brine
5. dry with materialdried (anhydrous sodium sulphate)
6. filtrationfiltered
7. customevaporated