| 摘要 |
<p>NEW MATERIAL:A benzoic acid derivative expressed by the formula (X is Cl or Br). EXAMPLE:2-Chloro-4,5-difluorobenzoic acid. USE:An intermediate for producing a fluorine-containing pyridonecarboxylic acid-based synthetic antimicrobial agent temafloxacin, etc. PREPARATION:4,5-Difluoroanthranilic acid is reacted with a strong acid and sodium nitrite to provide the corresponding diazonium salt, which is then decomposed using a cuprous halide expressed by the formula CuX to afford the benzoic acid derivative expressed by formula I.</p> |
