Preparation and properties of isomeric N-(4-substituted benzylidene)-4-ethynylanilines and 4-substituted N-(4-ethynylbenzylidene)anilines

4-Substituted N-(4-ethynylbenzylidene)anilines (4-HC=C-C6H4-CH=N-C6H4-4-R; R = Me, t-Bu, OMe, F, Cl, Br, I, CF3 and NO2) have been prepared by condens ation of 4-ethynylbenzaldehyde with appropriate anilines under mild conditi ons in good yields. The products obtained were fully characterized by GC-MS , IR, NMR and UV-VIS spectroscopies and their properties were compared with a series of 4-ethynyl-N-(4-substituted benzylidene)anilines (4-HC=C-C6H4-N =CH-C6H4-4-R; R = H, Me, t-Bu, F, Br, NO2, CN, NMe2). The influence of subs tituent R on spectroscopic characteristics is discussed.