反应详情

A mixture of 2.25 g of 3-acetyl-4-hydroxy-2H-1-benzopyran-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 2 hours and 30 minutes. After cooled 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 1.49 g of 4-hydroxy-3-[3-[3-chloro-4-(trifluoromethoxy)phenyl]-1-oxo-2-propenyl]-2H-1-benzopyran-2-one [Compound No. (1c-6)] was obtained as a yellow crystal.

1. temperaturewas heated
2. temperatureunder refluxing for 2 hours and 30 minutes
3. concentrationthe reaction mixture was concentrated under reduced pressure
4. customResulting crystals
5. washwere washed with 40 ml of t-butyl methyl ether