Hydrazine hydrate (1:1) → 7-(Trifluoromethyl)-1H-indazole

Participants

Reaction Steps

A solution of 2-fluoro-3-trifluoromethylbenzaldehyde (5 g, 26 mmol)), hydrazine hydrate (8.3 mL, 260 mmol) and DMAP (3.17 g, 26 mmol.) in 10 mL pyridine was heated at 100° C. for 24 hours. The cool reaction mixture was partitioned with EtOAc and 1 N HCl. The organic phase was washed with brine and dried with anhydrous sodium sulfate (Na2SO4). The organic phase was concentrated in vacuo to give 4.5 g of product. The crude product was recrystallized from Et2O/hexane to give the title compound (3.6 g, white solid, mp 90° C.).

Provenance & Evidence