Cesium carbonate → 2-Methyl-5-vinylpyridine

Temperatur

77.5 °C

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).

1. customThe flask was evacuated
2. custompurged with nitrogen (3 cycles)
3. temperaturecooled to room temperature
4. additionThe mixture was diluted with water (100 mL) and hexanes (50 mL)
5. extractionextracted with ether-hexanes (4:1, 50 mL)
6. washThe combined organic phases were washed with brine (25 mL)
7. dry with materialdried over Na2SO4
8. distillationdistilled at atmospheric pressure to a volume of ca. 10 mL
9. distillationThe residue was distilled under vacuum (90-100° C./20 Torr)

ORD-Eintrag

ord-d1036c6fb30a486a9e3807c9c00602bf

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08524703B2