Abstract: The Manganese (II) complex of 2-Amino-4-(4-methoxyphenyl)-5, 6, 7, 8-tetrahydro-7, 7-dimethyl-5-oxochromene-3-carbonitrile (AMC) was synthesized. The organic ligand AMC was previously synthesized using an environment friendly method using microwave irradiation. The Manganese complex MnIIAMC was characterized by different tools such as IR, electronic spectroscopy, elemental analysis, Thermal analysis and mass spectroscopy. The mode of metal binding shows that the Manganese binds to the ligand through the nitrogen atoms of the amino and cyanide groups. The Manganese complex MnIIAMC was used in the homogenous oxidation of the polyphenol 1,2,3-trihydroxybenzene in presence of the green oxidant H2O2 to produce a first-order rate constant kcat= 6.3×10-3s-1. The catalysis shows catalytic efficiency of 2.49 × 103 times compared to the autooxidation of THB.