Potassium Phosphate, Tribasic → 3-(3-fluoro-4-hydroxyphenyl)-5-nitro-1-trityl-1H-indazole

Participants

Reaction Conditions

Reaction Steps

A suspension of 3-bromo-5-nitro-1-trityl-1H-indazole 1AJ (10.0 g, 20.68 mmol), 3-fluoro-4-hydroxyphenylboronic acid 2AW (3.55 g, 22.78 mmol), Pd(dppf)Cl2 (1.6 g, 1.96 mmol) and K3PO4 (10.6 g, 4.99 mmol) in 200 mL of dioxane/H2O (4/1) was heated to 75° C. for overnight. After removal of most of the solvent, the black residue was diluted with EtOAc (250 mL) and H2O (60 mL). The resulting mixture was filtered through a pad of Celite. Additional 150 mL of EtOAc was used to wash the Celite cake. The filtrates were combined. The aqueous layer was separated and the organic layer was washed with brine, dried (MgSO4) and concentrated to give a green solid, which was recrystallized from CH2Cl2/hexane to give 3-(3-fluoro-4-hydroxyphenyl)-5-nitro-1-trityl-1H-indazole 3AW (8.1 g).

Provenance & Evidence