Synthesis, characterization and selective oxidation using a new copper (II) Schiff base complex derived from Alanine and 4-chloro3- formyl coumarin

A novel Schiff-base ligand (L: 2-[(4-chloro-2-oxo-2H-chromen-3-ylmethylene)-amino] propionic acid) was prepared from the reaction of 4-chloro3-formylcoumarin and alanine amino acid. Copper (II) complex was synthesized from the reaction of the ligand with Cu (OAc)2. H2O in ethanol. The ligand and its metal complex were characterized by elemental analysis (CHN), ICP, thermal analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), 1HNMR, and 13C NMR techniques. The complex was found to be an efficient catalyst and reusable in the selective oxidation of sulfides to the corresponding sulfoxides without the formation of any sulfone using the green oxidant, H2O2, at room temperature and under solvent-free conditions.