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