反应详情

温度

95 °C

A mixture of 4-bromo-2,5-difluorobenzoic acid (2.50 g, 10.6 mmol) and hydrazine (3.81 mL, 121 mmol) in N-methyl-2-pyrrolidinone (2 mL) was heated at 95° C. for 4 h. The cooled mixture was poured into vigorously stirred 6 M aqueous HCl (400 mL) which was cooled in an NaCl-ice bath. The resulting precipitate was collected by filtration, washed with 6 M aqueous HCl (200 mL) and dried under vacuum to give 4-bromo-5-fluoro-2-hydrazinylbenzoic acid hydrochloride as a yellow solid (1.88 g, 71% purity, 44% yield), used without further purification.

1. temperaturewas cooled in an NaCl-ice bath
2. filtrationThe resulting precipitate was collected by filtration
3. washwashed with 6 M aqueous HCl (200 mL)
4. customdried under vacuum