反应详情

2.9 g of triphenylphosphine was added to 3.6 g of compound (7) (14.9 mmol) prepared in Example 4 dissolved in 20 mL of chloroform and the mixture was reacted at 120° C. for 10 minutes by radiating with microwave radiation. And the mixture concentrated under reduced pressure to remove chloroform, and then crystallized from diethyl ether. The crystal was added to 5 mL of 40% formaldehyde, and 50% NaOH was slowly added dropwise to be a concentration of 1.7 N. After stirring for 2 hours, the resultant was extracted with ether, and concentrated under reduced pressure. The residue was separated by column chromatography (eluting solvent: chloroform/methanol=30/1) to obtain 2.5 g of 2,3-dichloro-5-vinylpyridine (yield 97%).

1. customthe mixture was reacted at 120° C. for 10 minutes
2. concentrationAnd the mixture concentrated under reduced pressure
3. customto remove chloroform
4. customcrystallized from diethyl ether
5. additionThe crystal was added to 5 mL of 40% formaldehyde, and 50% NaOH
6. additionwas slowly added dropwise
7. extractionthe resultant was extracted with ether
8. concentrationconcentrated under reduced pressure
9. customThe residue was separated by column chromatography (eluting solvent: chloroform/methanol=30/1)