Synthesis of regioisomeric 6,9-(chlorofluoro)-substituted benzo[<i>g</i>]quinoline-5,10-diones, benzo[<i>g</i>] isoquinoline-5,10-diones and 6-chloro-9-fluorobenzo[<i>g</i>]quinoxaline-5,10-dione
作者:A. Paul Krapcho、Cynthia E. Gallagher、Abdelhakim Hammach、Michael Ellis、Ernesto Menta、Ambrogio Oliva
DOI:10.1002/jhet.5570340105
日期:1997.1
Treatment of difluoro or chloro fluoro-substituted benzyl bromides 5a-c with zinc dust in tetrahydro-furan leads to the corresponding benzylic zinc bromides 6a-c. These organometallics on treatment with chlorosubstituted heterocyclic esters 4A and 4B mediated by nickel catalysis undergo couplings to yield dihalobenzyl substituted heterocyclic esters 7Aa-c and 7Ba-c. Treatment of 4c with 6c under Pd
在四氢呋喃中用锌粉处理二氟或氯氟取代的苄基溴化物5a-c,得到相应的苄基溴化锌6a-c。这些通过镍催化介导的用氯取代的杂环酯4A和4B处理的有机金属进行偶联,得到二卤代苄基取代的杂环酯7Aa-c和7Ba-c。在钯催化下用6c处理4c可得到7cc。通过将这些酯水解制得的酸8(经发烟硫酸处理)进行环化和氧化反应,得到所需的区域异构体二卤代杂环醌2。