Reaktion #67098

Reaktionsgleichung

potassium acetate

4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane

N-(5-Bromo-2-chloro-3-pyridinyl)methanesulfonamide

potassium acetate

4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane

→

title compound

Ausbeute 111.7%

{6-Chloro-5-[(methylsulfonyl)amino]-3-pyridinyl}boronic acid

Ausbeute 111.7%

Lösungsmittel

1,4-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITThe reaction was left
2. 2
   workup.STIRRINGthe mixture stirred at 95° C. overnight
3. 3
   TemperaturThe mixture was cooled to room temperature
4. 4
   Filtrationthe mixture was filtered through a hydrophobic frit
5. 5
   Sonstigethe solvent removed in vacuo
6. 6
   SonstigeThe residue was partitioned between water (250 ml) and dichloromethane (250 ml)
7. 7
   Sonstigethe organic layer was collected
8. 8
   Sonstigethe solvent removed in vacuo
9. 9
   Wascheneluting with 0-25% methanol in dichloromethane over 40 mins

Vorschrift

N-(5-Bromo-2-chloro-3-pyridinyl)methanesulfonamide (5 g, 17.51 mmol), potassium acetate (5.16 g, 52.5 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane (4.89 g, 19.26 mmol) and 1,1′-bis(diphenylphosphino)ferrocene palladium dichloride (1.281 g, 1.751 mmol) were placed in 1,4-dioxane (51 ml) and the mixture heated for 16 h at 90° C. The reaction was left stirring at 90° C. for a further 5 h. Further catalyst (0.3 g), potassium acetate (1.7 g) and 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane (1.5 g) were added and the mixture stirred at 95° C. overnight. The mixture was cooled to room temperature then the mixture was filtered through a hydrophobic frit and the solvent removed in vacuo. The residue was partitioned between water (250 ml) and dichloromethane (250 ml). the organic layer was collected and the solvent removed in vacuo. The residue was columned on silica (3×100 g) cartridges eluting with 0-25% methanol in dichloromethane over 40 mins gave the title compound as a dark brown oil (4.9 g).

Quelle