反应详情

A mixture of 1.85 g of 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one, 2.25 g of 3-chloro-4-(trifluoromethoxy)benzaldehyde, 20 ml of chloroform and 0.7 ml of piperidine was heated under refluxing for 4 hours. After cooling to room temperature, the reaction mixture was concentrated under reduced pressure, and the residue was subjected to column chromatography. Resulting crystals were washed with 40 ml of t-butyl methyl ether to obtain 0.40 g of 4-hydroxy-3-[3-[3-chloro-4-(trifluoromethoxy)phenyl]-1-oxo-2-propenyl]-6-methyl-2H-pyran-2-one [Compound No. (1a-6]) as a yellow crystal.

1. temperaturewas heated
2. temperatureunder refluxing for 4 hours
3. concentrationthe reaction mixture was concentrated under reduced pressure
4. customResulting crystals
5. washwere washed with 40 ml of t-butyl methyl ether