Water → 5-bromo-1H-indazole

Participants

Reaction Conditions

Reaction Steps

To an orange solution of 5-bromo-2-fluorobenzaldehyde (3.0 g, 14.78 mmol) in n-butanol (6 mL) was added hydrazine hydrate (11.1 g, 10.78 mL, 221.66 mmol) and the thick orange slurry was heated to 125° C. (became clear at 65° C.) in an oil bath for 21 h and cooled to rt. The mixture was poured into water (100 mL) and ethyl acetate (300 mL). The aqueous layer was isolated and extracted with ethyl acetate (100 mL). The combined organics were washed with brine, dried over Na2SO4 and concentrated. The product was isolated by column chromatography (33% ethyl acetate in hexanes) as a cream colored solid (0.86 g, 30%). LC-MS [M+H]+=197.1, RT=2.64 min.

Provenance & Evidence