反应详情

A mixture of 2-chloro-4-(4-methoxyphenyl)pyridine (660 mg) and bis(triphenyl-phosphine)nickeldichloride (200 mg) in anhydrous tetrahydrofuran (7.5 mL) is cooled to a temperature close to 0° C. A solution of methylmagnesiumbromide in tetrahydrofuran (2.6 M, 2 mL) is added slowly. The mixture is stirred at room temperature for two hours, concentrated under reduced pressure and dissolved in methyl tert-butyl ether (10 mL). Alkaloids are extracted with a 3N aqueous solution of hydrochloric acid (3 times 10 mL). Extracts are pooled, alkalinised and back extracted with methyl tert-butyl ether (3 times 20 mL) and dichloromethane (30 mL). Organic phases are dried over magnesium sulphate, concentrated under reduced pressure and purified over silica gel (eluent dichloromethane/methanol from 100/0 to 95/5). Fraction containing the expected product are pooled and concentrated under reduced pressure to give 385 mg of 4-(4-methoxyphenyl)-2-methylpyridine as a clear brown powder used without further purification.

1. temperatureis cooled to a temperature
2. customclose to 0° C
3. concentrationconcentrated under reduced pressure
4. dissolutiondissolved in methyl tert-butyl ether (10 mL)
5. extractionAlkaloids are extracted with a 3N aqueous solution of hydrochloric acid (3 times 10 mL)
6. extractionback extracted with methyl tert-butyl ether (3 times 20 mL) and dichloromethane (30 mL)
7. dry with materialOrganic phases are dried over magnesium sulphate
8. concentrationconcentrated under reduced pressure
9. custompurified over silica gel (eluent dichloromethane/methanol from 100/0 to 95/5)
10. additionFraction containing the expected product
11. concentrationconcentrated under reduced pressure