Reaktion #85728

Reaktionsgleichung

ethyl 5,6-dichloronicotinate

tributyl(1-ethoxyvinyl)stannane

→

ethyl 5-chloro-6-(1-ethoxyvinyl)nicotinate

Lösungsmittel

MeCN

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe reaction was sealed
2. 2
   SonstigeA dark color clear solution resulted
3. 3
   TemperaturThe reaction mixture was then cooled to 20° C.
4. 4
   Einengenconcentrated
5. 5
   workup.ADDITIONdiluted with EtOAc (200 mL)
6. 6
   Waschenwashed with water (50 mL) and brine (50 mL)
7. 7
   TrocknenThe organic was then dried (Na2SO4)
8. 8
   Einengenconcentrated

Vorschrift

To a suspension of ethyl 5,6-dichloronicotinate (5.26 g, 23.90 mmol) and tetraethylammonium-chloride (11.88 g, 71.7 mmol) in MeCN (50 mL) was added tributyl(1-ethoxyvinyl)stannane (9.50 g, 26.3 mmol) and PdCl2(PPh3)2 (0.671 g, 0.956 mmol). The reaction was sealed, heated at 80° C. for 5 hours. A dark color clear solution resulted. The reaction mixture was then cooled to 20° C., concentrated and diluted with EtOAc (200 mL), and washed with water (50 mL) and brine (50 mL). The organic was then dried (Na2SO4) and concentrated to give crude ethyl 5-chloro-6-(1-ethoxyvinyl)nicotinate. The residue was then dissolved in THF (100 mL) and HCl (20 mL, 3M in H2O) was added. The reaction mixture was stirred at 20° C. for 5 hours, and saturated NaHCO3 solution was added until pH=8. The mixture was then diluted with EtOAc (200 mL) and water (50 mL). The phases were separated and the aqueous layer was extracted with EtOAc (2×50 mL). The combined organics was washed with brine (20 mL), dried (Na2SO4) and concentrated to afford the desired product (3.56 g). LCMS m/z 228.5 (M+H)+, Rt 0.83 min.

Quelle