Substituted imidazonaphthyridine derivatives. I. C₁₉H₁₄F₃N₃, C₁₈H₁₀F₅N₃, C₁₈H₁₁ClF₃N₃ and C₁₈H₁₁BrF₃N₃

The structures of four 2,6,8-trisubstituted imidazonaphthyridine derivatives, 6-methyl-2-(4-methylphenyl)-8-trifluoromethylimidazo[1,2-a][1,8]naphthyridine, (I), 2-(3,4-difluorophenyl)-6-methyl-8-trifluoromethylimidazo-[1,2-a][1,8] naphthyridine, (II), 2-(4-chlorophenyl)-6-methyl-8-trifluoromethylimidazo[1,2-a][1,8]naphthyridine, (III), and 2-(4-bromophenyl)-6-methyl-8-trifluoromethylimidazo[1,2-a][1,8]naphthyridine, (IV), are reported. The molecules are planar and exist as dimers, formed through intermolecular C-H⋯N hydrogen bonds in all four cases. The trifluoromethyl group undergoes rotational disorder in (II)-(IV). The molecules are laid in two-dimensional planes in the crystal lattice with possible intermoleculear π-π interactions.