4-Aryl-8-hydroxyquinolines from 4-chloro-8-tosyloxyquinoline using a Suzuki–Miyaura cross-coupling approach

4-Chloro-8-tosyloxyquinoline was successfully cross-coupled with various arylboronic acids in anhydrous Suzuki–Miyaura conditions. The protective tosyl group was stable during the anhydrous coupling. The use of tosyl protection in association with anhydrous Suzuki–Miyaura reaction conditions allows the use of commercially available but relative inert 5-chloro-8-hydroxyquinoline for the synthesis of 5-phenyl-8-hydroxyquinoline. Deprotection could easily be made by using suitable nucleophiles to afford the final 5-phenyl and 4-aryl-8-hydroxyquinolines in high yields. Under acidic conditions the tosyloxy group is sufficiently stable to allow selective further modification of acid labile functional groups.