Synthesis and spectroscopic and structural characterization of three new 2-methyl-4-styrylquinolines formed using Friedlander reactions between (2-aminophenyl)chalcones and acetone

Three new 2-methyl-4-styryl­quinoline derivatives have been synthesized in high yields using Friedländer reactions between chalcones [1-(2-amino­phen­yl)-3-aryl­prop-2-en-1-ones] and acetone, and characterized using IR, ¹H and ¹³C NMR spectroscopy, and mass spectrometry, and by crystal structure analysis. In (E)-4-(4-fluoro­styr­yl)-2-methyl­quinoline, C₁₈H₁₄FN, (I), the mol­ecules are joined into cyclic centrosymmetric dimers by C—H⋯N hydrogen bonds and these dimers are linked into sheets by π–π stacking inter­actions. The mol­ecules of (E)-2-methyl-4-[4-(tri­fluoro­meth­yl)styr­yl]quinoline, C₁₉H₁₄F₃N, (II), are linked into cyclic centrosymmetric dimers by C—H⋯π hydrogen bonds and these dimers are linked into chains by a single π–π stacking inter­action. There are no significant hydrogen bonds in the structure of (E)-4-(2,6-di­chloro­styr­yl)-2-methyl­quinoline, C₁₈H₁₃Cl₂N, (III), but mol­ecules related by translation along [010] form stacks with an inter­molecular spacing of only 3.8628 (2) Å. Comparisons are made with the structures of some related com­pounds.