PURPOSE: To obtain the titled compound without causing the problems of local corrosion of the reactor, by oxidizing an alkyl-substituted aromatic aldehyde, etc. with molecular oxygen in an aqueous solvent in the presence of a catalyst containing bromine ion using zirconium metal coated with oxide layer as the material of the reactor.
CONSTITUTION: An aromatic polycarboxylic acid such as terephthalic acid, trimellitic acid, pyromellitic acid, etc. useful as a raw material of synthetic fibers, synthetic resins, high-performance plasticizers, polyesters, specialty plasticizers, polyimides, etc. easily, in one step, in high yield, by oxidizing an alkyl-substituted aromatic aldehyde such as p-tolualdehyde or an alkyl-substituted aromatic carboxylic acid such as toluic acid with molecular oxygen in an aqueous solvent in the presence of bromine ion or bromine ion and heavy metal ion such as manganese ion, cerium ion, etc. In the above reaction, zirconium metal coated its surface with oxide layer is used as a material of the reactor to suppress the generation of the corrosion of the reactor.
HATAYA MASANORI
TANAKA KAZUO
SAKAI YUKIO
HAMADA YASUSHI
