Further studies on the cyclization of aromatic azomethines ortho-substituted with a trifluoromethyl group: synthesis of 2, 4-di-or 2, 3, 4-trisubstituted quinolines
The scope and limitations of the novel synthetic route to quinolines (Strekowski et al. J. Org. Chem. 1990, 55, 4777) have been studied. A direct condensation of 2-(trifluoromethy1) aniline (1) with methyl aryl ketones, methyl heteroaryl ketones, ethyl aryl ketones, methyl vinyl ketones, 1-indanone, 1-tetralone, camphor, and cyclohexanone provides an easy access to the corresponding ketimines. An indirect one-pot preparation of dialkyl ...