抄録
It was assumed that the severence of an N-O bond in quinoline 1-oxide, while its oxygen still retained the electron octet, by the application of a proton or acyl group to quinoline 1-oxide, whose lone-pair electrons of the oxygen are bonded to functions with great electrophilic properties, would result in activation of 2- and 4-, as well as 3-position, of the quinoline to nucleophilic substitution by the resonance of extremely labile quinoline residue left with a nitrongen with sextet electrons (Chart 1). Under such assumption, the crystalline complex of quinoline 1-oxide and boron trifluoride was heated with phosphoric acid or tosyl chloride. When the complex was heated in orthophosphoric acid, a small amount of 3-quinolinol formed besides quinoline and carbostyril, while heating with tosyl chloride produced 3-(p-toluenesulfonyloxy) quinoline (prisms, m.p. 90-92°), besides carbostyril and 4-chloroquinoline.
