Cesium carbonate → 2-Methyl-5-vinylpyridine

Temperature

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 then 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, 3H) 5.35 (d, J=11.1 Hz, 1H) 5.86 (d, J=17.8 Hz, 1H) 6.74 (dd, J=17.8, 11.1 Hz, 1H) 7.27 (d, J=7.9 Hz, 1H) 7.84 (dd, J=8.3, 2.4 Hz, 1H) 8.40 (d, J=2.0 Hz, 1H).

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 record

ord-ea1702f7d3e94967a4870011a041b442

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08778959B2