Water → 5-(2,6-difluorophenyl)-1H-indazole
Reaction equation
[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1[C:9]1[CH:14]=[CH:13][C:12](F)=[C:11]([CH:16]=O)[CH:10]=1.O.O.[NH2:20][NH2:21]>>[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1[C:9]1[CH:10]=[C:11]2[C:12](=[CH:13][CH:14]=1)[NH:21][N:20]=[CH:16]2Participants
4
Conditions
- Temperature
- 120 °C
Procedure
2′,4,6′-trifluorobiphenyl-3-carbaldehyde (160 g, 695.01 mmol) was taken in hydrazine hydrate (800 mL) and heated to 120° C. for 8 h. The reaction mixture was cooled to RT. Water was added to the reaction mixture and extracted with EtOAc (2×500 mL). Organic layer was washed with brine and dried over Na2SO4. The organic layer was concentrated and purified by column using silica (100-200 mesh) and 0-15% EtOAc-hexane to provide 5-(2,6-difluoro-phenyl)-1H-indazole (40.8 g, 25.4% yield). MS (ESI, pos. ion) m/z: 231.1 (M+1).