Isophthalic acid from m-xylene

Whereas benzene and toluene serve as the raw materials for a wide range of products, applications for the three xylene isomers, o-, m- and p-xylene, are basically limited to chemicals arising through oxidation, i.e. phthalic anhydride (PA) from o-xylene, isophthalic acid from m-xylene and terephthalic acid from p-xylene. 

A more recent modification of the Willgerodt reaction describes the preparation of acids from aromatic hydrocarbons using aqueous base and sulfur [6]. An example is the preparation of isophthalic acid from m-xylene using aqueous ammonia, sulfur, and water. 

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