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Example 6: This example describes in detail the synthesis of 2-bromoterephthalic acid using 2-bromo-1,4-dimethylbenzene as starting material. In a stirred autoclave equipped with an internal cooling coil and a reflux condenser, 2-bromo-1,4-dimethylbenzene (541 mmol) was mixed with 2-bromo-1,4-dimethylbenzene (541 mmol) containing cobalt(II) acetate tetrahydrate (0.625 mmol), manganese(II) acetate tetrahydrate (0.625 mmol), zirconium(IV) acetate (0.15 mmol) and sodium bromide (0.525 mmol) in a 500 g of 97% acetic acid solution were mixed. The mixture was stirred at a constant rate using a gas dispersion stirrer to optimize gas mixing, followed by heating the mixture to 150 °C for 2 h and maintaining it for 2 h, and then ramping up to 180 °C for 4 h. The mixture was heated to 150 °C for 2 h and then ramped up to 180 °C for 4 h. During the heating of the reaction, air was continuously vented at a back pressure of 400 psig (2.76 MPa). Upon completion of the reaction, the pressure was slowly released and the reactor was cooled to 50°C. The reaction products were drained and the reactor was rinsed with 50 g of acetic acid in two passes to collect the residual products. The white solid product was collected by diafiltration, washed with water and dried under vacuum, resulting in 113 g (85% yield) of a white solid of 2-bromoterephthalic acid with 99% purity, the structure of which was confirmed by 1H NMR.