反応 #66063

反応方程式

potassium vinyltrifluoroborate

5-bromo-2-methylpyridine

triphenylphosphine

Cs2CO3

→

title compound

2-methyl-5-vinylpyridine

溶媒

Water

反応条件

後処理

1. 1
   その他The flask was evacuated
2. 2
   その他purged with nitrogen (3 cycles)
3. 3
   温度cooled to room temperature
4. 4
   workup.ADDITIONThe mixture was diluted with water (100 mL) and hexanes (50 mL)
5. 5
   抽出extracted with ether-hexanes (4:1, 50 mL)
6. 6
   洗浄The combined organic phases were washed with brine (25 mL)
7. 7
   乾燥dried over Na2SO4
8. 8
   workup.DISTILLATIONdistilled at atmospheric pressure to a volume of ca. 10 mL
9. 9
   workup.DISTILLATIONThe residue was distilled under vacuum (90-100° C./20 Torr)

実験手順

Water (10 mL) was added to a mixture of potassium vinyltrifluoroborate (6.35 g, 47.4 mmol, Aldrich), 5-bromo-2-methylpyridine (8.00 g, 46.5 mmol,), triphenylphosphine (0.732 g, 2.79 mmol) and Cs2CO3 (45.5 g, 140 mmol) in a 500 mL round-bottom flask with stir bar. The flask was evacuated and purged with nitrogen (3 cycles), and the mixture was heated under nitrogen at 75-80° C. for 19 hours, and then cooled to room temperature. The mixture was diluted with water (100 mL) and hexanes (50 mL), and the aqueous layer was drawn off and extracted with ether-hexanes (4:1, 50 mL). The combined organic phases were washed with brine (25 mL), dried over Na2SO4 and distilled at atmospheric pressure to a volume of ca. 10 mL. The residue was distilled under vacuum (90-100° C./20 Torr) to provide the title compound: 1H NMR (400 MHz, methanol-d4) δ ppm 2.51 (s, 3 H) 5.35 (d, J=11.1 Hz, 1 H) 5.86 (d, J=17.8 Hz, 1 H) 6.74 (dd, J=17.8, 11.1 Hz, 1 H) 7.27 (d, J=7.9 Hz, 1 H) 7.84 (dd, J=8.3, 2.4 Hz, 1 H) 8.40 (d, J=2.0 Hz, 1 H).

出典