反应详情

To a well stirred ice-cooled mixture of 0.1 mole of triphenylphosphine and 0.1 mole of potassium t-butoxide in 250 ml. of heptane is added over thirty minutes a mixture of 0.1 mole of chloroform in 200 ml. of heptane. The resulting mixture is concentrated in vacuo at 15°-20° to a volume of about 100 ml. and a solution of 0.1 mole of 2,2,8-trimethyl-4H-1,3-dioxino[4,5-c]-pyridine-5-carboxaldehyde in 250 ml. of heptane is added. The reaction mixture was heated at 40°-50° for 5 hours, then cooled, filtered, and concentrated in vacuo to give crude product. Chromatography on silica gel and elution with ether-petroleum ether (10-50%) gives pure 5-(2,2-dichlorovinyl)-2,2,8-trimethyl-4H-1,3-dioxino[4,5-c]pyridine.

1. temperatureTo a well stirred ice-cooled
2. concentrationThe resulting mixture is concentrated in vacuo at 15°-20° to a volume of about 100 ml
3. temperatureThe reaction mixture was heated at 40°-50° for 5 hours
4. temperaturecooled
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give crude product
8. washChromatography on silica gel and elution with ether-petroleum ether (10-50%)