Process for the production of terephthalic dialdehyde by hydrolysis of .alpha.,.alpha.,.alpha.',.alpha.'-tetrachloro-p-xylene, which comprises contacting .alpha.,.alpha.,.alpha.',.alpha.'-tetrachloro-p-xylene and steam in a reaction zone at a temperature and for a time sufficient for hydrolysis of the .alpha.,.alpha.,.alpha.',.alpha.'-tetrachloro-p-xylene to form said dialdehyde.
The present invention provides a process for the production of unsubstituted or substituted o-phthalaldehydes by hydrolysis of .alpha.,.alpha., .alpha.',.alpha.'-tetrahalogeno-o-xylenes with a carboxylate in an aqueous medium in the presence of a phase transfer catalyst and an organic base.
A process for the preparation of o-phthalaldehydes is disclosed comprising the steps of (1) halogenating an o-xylene and (2) hydrolysis of the resulting tetrahalogeno-o-xylene.
