Hydrazine hydrate (1:1) → 3-pyridin-2-yl-7-(trifluoromethyl)-2H-indazole

Participants

Reaction Steps

Next, a solution of (6-fluoro-5-trifluoromethyl-cyclohexa-2,4-dienyl)-pyridin-2-yl-methanone (1.5 g, 5.6 mmol), 4-dimethylaminopyridine (0.5 g) and hydrazine hydrate (5 mL) in pyridine (20 mL) was heated at 100° C. overnight. The reaction mixture was cooled and diluted with brine and EtOAc. The organics were washed with water (3×25 mL), then brine (25 mL) and dried over MgSO4. The reaction mixture was concentrated in vacuo and purified by flash chromatography (silica gel 60, EtOAc/CH2Cl2, 19:1) to afford 3-pyridin-2-yl-7-(trifluoromethyl)-2H-indazole as a pale yellow solid (1.1 g, 76%).

Provenance & Evidence