Tributylvinyltin → 2-Vinyl-4-picoline

Temperatur

100 °C

A yellow mixture of 2-bromo-4-methyl-pyridine (Aldrich, 5.2 9, 30.5 mmol, 1.0 eq), 2,6-di-tert-butyl-4-methyl-phenol (Aldrich, 67 mg, 0.3 mmol, 1 mol %), tributyl-vinyl-stannane (Aldrich, 26.8 mL, 91.5 mmol, 3.0 eq) and tetrakis(triphenylphosphine) palladium (0) (Strem, 1.8 9, 1.5 mmol, 5 mol %) in toluene (100 mL) was degassed and purged with argon. An amber solution was obtained after the mixture was warmed to 100° C. The reaction mixture was quenched after 18 hours by the addition of 1.0 M HCl. The acidic extract was washed with ether, adjusted to pH 9 with solid sodium bicarbonate, and extracted with ethyl acetate. The organic extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product (3.7 g of a brown oil) was purified by flash chromatography (silica) and eluted with 0–5% ethyl acetate-dichloromethane, which gave a clear oil (1.9 g, 53%). 1H NMR (DMSO-d6, 300 MHz) δ 8.39 (1H, d, J=4.9 Hz), 7.33 (1H, s), 7.10 (1H, dd, J=5.0, 0.8 Hz), 6.77 (1H, dd, 17.5, 10.8 Hz), 6.20 (1H, dd, J=17.5, 1.7 Hz), 5.44 (1H, dd, J=10.8, 1.8 Hz), 2.31 (3H, s). ESIMS m/z 120 (M+H)+.

1. customwas degassed
2. custompurged with argon
3. customAn amber solution was obtained after the mixture
4. customThe reaction mixture was quenched after 18 hours by the addition of 1.0 M HCl
5. extractionThe acidic extract
6. washwas washed with ether
7. extractionextracted with ethyl acetate
8. washThe organic extracts were washed with brine
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated under reduced pressure
12. customThe crude product (3.7 g of a brown oil) was purified by flash chromatography (silica)
13. washeluted with 0–5% ethyl acetate-dichloromethane, which

ORD-Eintrag

ord-753577577dad4faeaf8dec6be43f749f

Quelldatensatz

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07053107B2