反应详情

Chloromethyl acetate (2.2 ml) was added to a stirred solution of 3-bromo-4-oxo-6-phenyl-4H-pyran-2-carboxylic acid (5.9 g) and triethylamine (2.9 ml) in dry DMF (40 ml). The solution was heated at 70°-80° C. for 3 hours, then poured on to ice-water and extracted with ethyl acetate. The extract was washed with sodium bicarbonate solution, dried and evaporated, and the residue was crystallised from ethanolwater. The crude product was purified by chromatography on silica-gel and recrystallisation from ethyl acetate-petroleum ether 60°-80° C. gave the title product as white needles (mp 121° C.).

1. temperatureThe solution was heated at 70°-80° C. for 3 hours
2. extractionextracted with ethyl acetate
3. washThe extract was washed with sodium bicarbonate solution
4. customdried
5. customevaporated
6. customthe residue was crystallised from ethanolwater
7. customThe crude product was purified by chromatography on silica-gel and recrystallisation from ethyl acetate-petroleum ether 60°-80° C.