反应详情

A mixture of 2.43 g (13 mmol) of 2-cyano-7- hydroxy-4-oxo-4H-1-benzopyran, 2.04 g (13 mmol) of 3-chlorobromopropane and 1.80 g (13 mmol) of potassium carbonate was refluxed in 250 ml dry acetone overnight with heating. After evaporating to dryness, the residue was extracted with chloroform (3×100 ml), and dried with sodium sulfate. The chloroform solution was evaporated to one-third of the original volume to which was added n-hexane. The white precipitate was collected by filtration, washed with n-hexane and dried in vacuum to obtain 2-cyano-7-(3-chloropropyloxy)-4-oxo-4H-1-benzopyran (yield 51%).

1. temperaturewith heating
2. customAfter evaporating to dryness
3. extractionthe residue was extracted with chloroform (3×100 ml)
4. dry with materialdried with sodium sulfate
5. customThe chloroform solution was evaporated to one-third of the original volume to which
6. additionwas added n-hexane
7. filtrationThe white precipitate was collected by filtration
8. washwashed with n-hexane
9. customdried in vacuum