반응 #1144315

반응 방정식

(E)-5-bromo-2,3-difluorobenzaldehyde O-methyl oxime

hydrazine hydrate

→

5-bromo-7-fluoro-1H-indazole

용매

THF

반응 조건

후처리

1. 1
   기타the organic solvent was evaporated
2. 2
   workup.ADDITIONThe resulting mixture was diluted with EtOAc (400 mL)
3. 3
   세척washed with water (150 mL)
4. 4
   건조dried over Na2SO4
5. 5
   농축concentrated in vacuo
6. 6
   기타The residue was purified by column chromatography on silica gel (0˜20% EtOAc in petroleum ether)

실험 절차

A mixture of (E)-5-bromo-2,3-difluorobenzaldehyde O-methyl oxime (19.65 g, 78.6 mmol), hydrazine hydrate (80 mL), and dry THF (80 mL), was heated at 90° C. for 84 h. Work-up: the organic solvent was evaporated. The resulting mixture was diluted with EtOAc (400 mL), washed with water (150 mL), dried over Na2SO4, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (0˜20% EtOAc in petroleum ether) to give 5-bromo-7-fluoro-1H-indazole as a white solid (9.3 g). 1H NMR (300 MHz, CDCl3): δ 13.83 (br, 1H), 8.16 (s, 1H), 7.87 (s, 1H), 7.45 (d, 1H).

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