A domino three-component condensation of ortho-haloacetophenones with urea or amines: a novel one-pot synthesis of halogen-substituted quinolines

Halogen-substituted quinolines have been synthesized in good yields by the condensation and cyclization of two molecules of ortho-haloacetophenones with urea or primary amines. The formation of halogen-substituted quinolines takes place through the unexpected catalyst-free cleavage of C(sp²)-X (X=Cl, Br), α-C(sp³)-H bonds and formation of C-C, C-N bonds in a selective manner. The attractive features of the present synthetic method for halogen-substituted quinolines include catalyst-free, one-pot process, easy availability of starting materials, and introduction of halogen on the quinoline ring for further transformation.