This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles.

The reaction conditions also lead to a second esterification, producing dimethyl terephthalate, which could be hydrolysed to terepthalic acid.

The combination of bromine and acetic acid is highly corrosive, requiring specialized reactors, such as those lined with titanium.

A mixture of p-xylene, acetic acid, the catalyst system, and compressed air is fed to a reactor.

The resulting oxygen-based radicals abstract hydrogen from a methyl group, which have weaker C–H bonds than does the aromatic ring.

Atmospheric air can be used in its place, but once reacted needs to be purified of toxins and ozone depleters such as methylbromide before being released.

Additionally, the corrosive nature of bromides at high temperatures requires the reaction be run in expensive titanium reactors.

Because CO2 is a better flame inhibitor than N2, a CO2 environment allows for the use of pure oxygen directly, instead of air, with reduced flammability hazards.

Use of supercritical water instead of acetic acid as a solvent diminishes environmental impact and offers a cost advantage.

[21] Lummus (now a subsidiary of McDermott International) has reported a route from the dinitrile, which can be obtained by ammoxidation of p-xylene.

Combined with the previously known PETase and MHETase, a full pathway for PET plastic degradation can be engineered.