Process for production of polycarboxylic aromatic acids

A liquid phase process for the co-preparation of an aliphatic monocarboxylic acid of from 2 to 6 carbon atoms and an aromatic polycarboxylic acid which comprises reacting in liquid phase a lower aliphatic alkanol of 2 to 6 carbon atoms and a polyalkyl aromatic in a reaction zone containing a cobalt-manganese-bromine catalyst, wherein weight ratio of said cobalt, calculated as elemental cobalt, is in the range of from about 0.2 to about 10 milligram atoms per gram mole of said polyalkyl aromatic, weight ratio of said manganese, calculated as elemental manganese, is in the range of from about 0.2 to about 10 milligram atoms per milligram atom of cobalt and weight ratio of said bromine, calculated as elemental bromine, is in the range of from about 0.2 to about 1.5 milligram atoms of total cobalt and manganese with an oxygen-containing gas in a residence time of from about 10 minutes to about 240 minutes, in the presence of said catalyst at a temperature of from about 250.degree. F. to about 465.degree. F., gauge pressure within the range of from about 0 kg/cm.sup.2 to about 35 kg/cm.sup.2, said reaction zone containing a solvent comprising water and an aliphatic monocarboxylic acid of 2 to 6 carbon atoms wherein the weight ratio of said solvent mixture to said polyalkyl aromatic is in the range of from 19:1 to about 1:1, and recovering reaction products comprising a monocarboxylic acid of from 2 to 6 carbon atoms and an aromatic polycarboxylic acid.