Reaktion #306459

Reaktionsgleichung

2-bromo-5-chloropyridine

cesium carbonate

2,3-difluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

→

5-(5-chloropyridin-2-yl)-2,3-difluoropyridine

Ausbeute 68.0%

Lösungsmittel

1,4-dioxane

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture was flushed with argon
2. 2
   Sonstigesealed
3. 3
   EinengenThe mixture was concentrated
4. 4
   workup.ADDITIONdiluted with dichloromethane
5. 5
   Waschenwashed with water
6. 6
   EinengenOrganic extracts were concentrated
7. 7
   Sonstigepurified by MPLC (eluted with 0-10% methanol in dichloromethane)

Vorschrift

To a pressure vessel was added 2-bromo-5-chloropyridine (3.0 g, 16 mmol), cesium carbonate (15 g, 47 mmol), 1,1′-bis(diphenylphosphino)ferrocene-palladium(ii) dichloride dichloromethane complex (2.5 g, 3.1 mmol), and 2,3-difluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (4.5 g, 19 mmol) in 1,4-dioxane (120 mL) and water (22 mL). The mixture was flushed with argon, sealed and stirred at 90° C. for three hours. The mixture was concentrated, diluted with dichloromethane and washed with water. Organic extracts were concentrated and purified by MPLC (eluted with 0-10% methanol in dichloromethane) to yield 5-(5-chloropyridin-2-yl)-2,3-difluoropyridine as a yellow solid (2.4 g, 68%). MS m/z=227.2 [M+1]+. Calc'd for C10H5ClF2N2: 226.6.

Quelle