Potassium Phosphate, Tribasic → 3-(2-fluoro-pyridin-4-yl)-5-nitro-1-trityl-1H-indazole

Participants

Reaction Conditions

Reaction Steps

3-Bromo-5-nitro-1-trityl-1H-indazole 3BI (15.64 g, 32.3 mmol), 2-fluoro-4-pyridine boronic acid 2BV (5.0 g, 35.5 mmol), K3PO4 (17.1 g, 80.7 mmol) and Pd(dppf)Cl2 (2.64 g, 3.23 mmol) was mixed in dioxane/H2O (240 mL/60 mL) at rt and heated at 80° C. overnight. The reaction mixture was cooled to rt and concentrated to a small volume. The residue was partitioned between ethyl acetate (200 mL) and brine (150 mL). The organic layer was washed with brine, dried (MgSO4) and filtered. The resulting filtrate was concentrated and the residue was purified on silica gel column eluting with hexanes, 5% ethyl acetate in hexanes, 10% ethyl acetate in hexanes sequentially to yield a yellow solid 3BV (3.33 g, 64%).

Provenance & Evidence