Реакция #162273

Уравнение реакции

Methyl 4-amino-5,6-dichloro-3-iodopicolinate

vinyltributylstannane

→

title compound

Выход 184.6%

methyl 4-amino-5,6-dichloro-3-vinylpicolinate

Выход 184.6%

Растворители

ethyl acetate

Условия реакции

Обработка

1. 1
   ТемператураThe reaction mixture was heated
2. 2
   Температураat reflux for 8 hours
3. 3
   ДругоеThe cooled reaction mixture
4. 4
   ДругоеThe phases were separated
5. 5
   Экстракцияthe aqueous phase was extracted with ethyl acetate
6. 6
   ПромывкаThe combined organic phases were washed with saturated sodium chloride
7. 7
   Сушкаdried over sodium sulfate
8. 8
   Концентрированиеconcentrated under vacuum
9. 9
   ДругоеThe crude product was purified by flash chromatography (SiO2, ethyl acetate/hexane)

Методика

Methyl 4-amino-5,6-dichloro-3-iodopicolinate (0.5 g, 1.4 mmol), vinyltributylstannane (530 μl, 0.57 mmol, 1.8 mmol), and bis(triphenylphosphine)palladium(II) chloride (0.10 g, 0.1 mmol) were combined in nitrogen-deaerated 1,2-dichloroethane (10 mL). The reaction mixture was heated at reflux for 8 hours. The cooled reaction mixture was diluted with ethyl acetate (30 mL) and stirred with 15% KHF2 solution (10 mL) for 30 minutes. The phases were separated and the aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with saturated sodium chloride, dried over sodium sulfate, and concentrated under vacuum. The crude product was purified by flash chromatography (SiO2, ethyl acetate/hexane) to afford the title compound as a tan solid (0.26 g, 73%): mp 96-97° C.; 1H NMR (400 MHz, CDCl3) δ 6.85 (dd, J=18.1, 11.5 Hz, 1H), 5.72 (dd, J=11.5, 1.3 Hz, 1H), 5.53 (dd, J=18.1, 1.3 Hz, 1H), 5.19 (s, 2H), 3.91 (s, 3H); EIMS m/z 246 ([M−H)−].

Источник