Reaktion #1552873

Reaktionsgleichung

tert-butyl 5-bromo-3-iodo-1H-indazole-1-carboxylate

4-pyridineboronic acid

K3PO4

→

5-bromo-3-(pyridin-4-yl)-1H-indazole

Ausbeute 70.4%

Lösungsmittel

dioxane

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a 500 ml round bottom flask equipped with a magnetic stir bar
2. 2
   FiltrationUpon completion, the reaction mixture was filtered through celite
3. 3
   Waschenwashed with water (3×100 ml)
4. 4
   TrocknenThe organic phase was then dried over anhydrous MgSO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated to dryness
7. 7
   Sonstigeto give a crude product
8. 8
   Sonstigepurified

Vorschrift

To a 500 ml round bottom flask equipped with a magnetic stir bar was added tert-butyl 5-bromo-3-iodo-1H-indazole-1-carboxylate (6.00 g, 14.2 mmol), followed by the additions of 4-pyridineboronic acid (1.92 g, 15.6 mmol), PdCl2(dppf) (1.16 g, 1.4 mmol) and K3PO4 (9.03 g, 42.5 mmol). The mixture was dissolved in a mixture of 160 ml of dioxane and 40 ml of H2O and stirred overnight at 80° C. Upon completion, the reaction mixture was filtered through celite and washed with water (3×100 ml). The organic phase was then dried over anhydrous MgSO4, filtered and concentrated to dryness to give a crude product. The crude product was column purified to give 5-bromo-3-(pyridin-4-yl)-1H-indazole (2.74 g) as a de-BOc product.

Quelle