A New Approach Towards Synthesis of Some Novel “Upper Rim” Functionalized Calix{4}resorcinarene Schiff-bases

Synthesis of new “upper rim” functionalized calix{4}resorcinarene Schiff-bases has been carried out by reacting tetraaminocalix{4}resorcinarene with different aromatic aldehydes in ethanol at reflux temperature. The tetra-aminocalix{ 4}resorcinarene, which can serve as very good precursor for various derivatizations at the extra annular position, was synthesized for the first time through tetra-azo intermediate, by first introducing the azo functionality at the upper rim, and subsequent reduction with Na2S2O4 in aq. NaOH. Synthesized Schiff-bases were characterized by elemental analysis, FT-IR, NMR and Mass spectral data. Their complexation ability with Cu(II) is also investigated.