PURPOSE: To obtain in high yield the tilted compound, by dehalogenating and dimerizing an aromatic compound containing at least one halogen nucleus in the presence of a palladium catalyst, water and a polyhydric alcohol and/or formaldehyde.

CONSTITUTION: An aromatic compound (e.g., chlorobenzene, etc.,) containing at least one halogen atom at an aromatic nucleus carbon is dehalogenated and dimerized in the presence of a palladium catalyst (especially palladium- active carbon catalyst is preferable and amount of it used is preferably 30W0.1mg atom calculated as Pd atom based on 1mol aromatic halogen compound), water and a polyhydric alcohol (e.g., ethylene glycol, glycerin, etc.) and/or a formaldehyde (e.g., paraformaldehyde, formalin, to give a dimer of the aromatic compound. Preferably a halogen acceptor (e.g., NaOH, etc.,) is also used in the reaction.

USE: A raw material for heat-resistant polyimide resin.