Triphenylphosphine → 6-bromo-4-methylene-3,4-dihydro-2H-pyrano[3,2-b]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred mixture of PPh3 (67.6 g, 0.258 mol), KOAc (42 g, 0.43 mol), Pd(OAc)2 (1.94 g, 8.6 mmol) and Et4NCI (28.6 g, 0.172 mmol), was added 2,6-dibromo-3-(but-3-enyloxy) pyridine (26.4 g, 0.086 mol) in anhydrous DMF (300 mL). The mixture was heated at 105° C. for 18 hours. After cooling to ambient temperature, the mixture was dissolved in Ethyl acetate, washed with water and brine, dried over Na2SO4, and concentrated in vacuo. The crude product was purified by silica gel chromatography (petroleum) to afford the title compound as oil (4.35 g, 22%). 1H NMR (400 Mz, DMSO-d6): δ 2.74 (t, J=5.4, 2H); 4.20 (t, J=6, 2H); 5.12 (s, 1H); 5.98 (s, 1H); 7.24 (d, J=7.5, 1H); 7.40 (d, J=7.5, 1H).

Herkunft & Nachweise