| 摘要 |
<p>NEW MATERIAL:1,4-Dihydro-4-oxoquinoline of formula I (X, Y are identical or different and F or Cl). EXAMPLE:8-Bromo-5-chloro-6-fluoro-4-oxo-1,4-dihydroquinoline. USE:It is used as a synthetic intermediate of a novel antibacterial, 9-halogeno-5- alkyl-8-unsubstituted through trisubstituted piperazinyl-benzo[ij]quinolidine-2- carboxylic acid. PREPARATION:An aniline of formula II is allowed to react with 2,2-dimethyl-1,3- dioxane-4,6-dione and ethyl orthoformate, preferably at 50-110 deg.C at 1-3 (the dione, formate/the aniline molar ratio respectively to give a compound of formula III. The product is heated in a heat medium such as rape oil, preferably at 170-260 deg.C to effect thermal ring closure into the compound of formula I.</p> |
