β-diketone (βd) is prepared using the name reaction Baker-Venkataraman transformation reaction. In this present work, ester (c’) was prepared when 1-(2-Hydroxy-5-methyl-phenyl)-ethanone (a’) was treated with 4-Propoxy-benzoic acid (b’) at 0 °C to 10 °C. (c’) on Baker-Venkataraman transformation to give β-diketone ligand (L’) named as 1-(2-Hydroxy-5-methyl-phenyl)-3-(4-propoxy-phenyl)-propane-1,3-dione. Bidentate ligand (L’) treated with Cu (II) nitrate gives Cu (II) complex (CuL’). (L’) shows tautomerism, this tautomerism phenomenon was studied using FTIR and NMR. Because of enol serve as ligand (L’) in the synthesis of (CuL’). The prepared (L’) can be characterized by HR-MS, elemental analysis, 1H, 13C, DEPT, D2O exchange, FTIR. The antibacterial, antifungal, antioxidant, anti-inflammatory property of (CuL’) is studied.