Synthesis of 8‐hydroxyquinolines with amino and thioalkyl functionalities at position 4
作者:Walaa A. E. Omar、Juha P. Heiskanen、Osmo E. O. Hormi
DOI:10.1002/jhet.5570450247
日期:2008.3
Six 8-hydroxyquinolines with amino and thioalkylfunctionalities at position4 have been prepared. The synthesis starts with chlorination of the readily available 4-hydroxy-8-tosyloxyquinoline to give 4-chloro-8-tosyloxyquinoline in 94% yield. Treatment of the 4-chloro-8-tosyloxyquinoline with sulphur and nitrogen nucleophiles produces the target 4-amino and 4-thioalkyl-8-hydroxyquinolines in more
A practical and efficient protocol for Ag/Ru-cocatalyzed regioselective C-H amination of 8-hydroxyquinoline esters with pyrazoles was developed, This reaction proceeded smoothly via a photoredox-mediated direct C-H/N-H oxidative coupling process. The remarkable features of this reaction include the wide substrate scope, mild reaction conditions and high regioselectivity at the C4 site of the quinolinyl