Reaktion #989721

Reaktionsgleichung

7-bromo-2,3-dimethyl-2H-indazole

2,4,6-trimethylphenyl boronic acid

potassium phosphate

2-dicyclohexylphosphino-2′-(N,N-dimethylamino)biphenyl

→

2,3-dimethyl-7-(2,4,6-trimethyl-phenyl)-2H-indazole

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas evacuated
2. 2
   workup.ADDITIONback-filled with nitrogen
3. 3
   workup.ADDITIONToluene (50 mL) was added
4. 4
   Temperaturto cool
5. 5
   workup.ADDITIONEther (200 mL) was added
6. 6
   Sonstigethe yellow solution was decanted from a dark granular solid
7. 7
   WaschenThe organic layer was sequentially washed with 200 mL of a 10% aqueous NaOH solution and 200 mL of a saturated aqueous NaCl solution
8. 8
   Trocknendried over MgSO4
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated to a pale yellow solid

Vorschrift

A flask containing 7-bromo-2,3-dimethyl-2H-indazole (3.23 g, 14.4 mmol), 2,4,6-trimethylphenyl boronic acid (3.51 g, 21.4 mmol), freshly ground potassium phosphate (6.04 g, 28.5 mmol), 2-dicyclohexylphosphino-2′-(N,N-dimethylamino)biphenyl (0.225 g, 0.572 mmol), and palladium(II) acetate (0.032 g, 0.14 mmol) was evacuated and back-filled with nitrogen. Toluene (50 mL) was added, and the yellow-orange mixture was stirred at 100° C. for 22 h then allowed to cool. Ether (200 mL) was added, and the yellow solution was decanted from a dark granular solid. The organic layer was sequentially washed with 200 mL of a 10% aqueous NaOH solution and 200 mL of a saturated aqueous NaCl solution, dried over MgSO4, filtered, and concentrated to a pale yellow solid. Column chromatography (0→33% EtOAc/hexanes) afforded 2,3-dimethyl-7-(2,4,6-trimethyl-phenyl)-2H-indazole as an off-white solid (7: R=R′=Me, Ar=2,4,6-trimethylphenyl; 3.03 g, 79%; m.p. 162-164).

Quelle