Synthesis of Substituted 8-Methoxyquinolines by Regioselective Bromine-Lithium Exchange of 5,7-Dihalo-8-methoxyquinolines and 7-Bromo-8-methoxyquinoline
作者:François Trécourt、Marc Mallet、Florence Mongin、Guy Quéguiner
DOI:10.1055/s-1995-4053
日期:1995.9
Reaction of phenyllithium with 7-bromo-8-methoxyquinoline, 5,7-dibromo-8-methoxyquinoline and 5,7-diiodo-8-metehoxyquinoline has been studied. Thus, bromine-lithium exchange of 7-bromo-8-methoxyquinoline gave the 7-lithio-8-methoxyquinoline which reacted with various electrophiles to afford 7-substituted-8-methoxyquinolines 3a-e. The same procedure was also applied to 5,7-dibromo-8-methoxyquinoline, which because of the high regioselectivity of the reaction, led to 7-substituted 5-bromo-8-methoxyquinolines 4a-f; one of them was used for the preparation of a pyridopyranoquinoline.
苯基锂与7-溴-8-甲氧基喹啉、5,7-二溴-8-甲氧基喹啉及5,7-二碘-8-甲氧基喹啉的反应已被研究。因此,7-溴-8-甲氧基喹啉的溴锂交换生成7-锂代-8-甲氧基喹啉,其与多种亲电试剂反应得到7-取代-8-甲氧基喹啉3a-e。同样的步骤也应用于5,7-二溴-8-甲氧基喹啉,由于反应的高度位选择性,得到了7-取代的5-溴-8-甲氧基喹啉4a-f;其中一种用于制备吡啶并吡喃喹啉。