The reaction of ferric chloride with uric acid giving ferrous ions, urea and oxalic acid, the Neubauer Reaction, has been developed in two recent spectroscopic techniques for uric acid determination. However, the reaction mechanism with uric acid has not been advanced. We provide the electron flow, step by step, from uric acid to the end products. Each step is commented, as well as other theoretical initial reaction sites. A substituted aziridinone is an interesting intermediate, and the formation of parabanic acid as precursor of the end products is in accord with experimental data.