PALLADIUM CATALYZED CARBONYLATION OF CONJUGATED DIENES AND RECIRCULATION OF THE CATALYST

摘要

ABSTRACT OF THE DISCLOSURE: A process for preparing carboxylic esters .beta., .gamma.-Unsaturated by carbonylation of conjugated dienes with carbon monoxide in the presence of an alcohol, a halogenated hydracid and a palladium catalyst, followed a distillation ope-ration in the presence of a chloride or a bromide quaternary onium fuse in the carbonylation conditions with recovery of a gaseous phase tale-nant the carboxylic esters .beta., .gamma.-unsaturated and a homogeneous liquid phase containing chloride or quaternary onium bromide, palladium catalyst and non-volatile heavies and recycling in the carbonyla-tion medium of a liquid mixture containing the chloride or bromide onium quaternary and the palladium catalyst after having possibly removed the heavy products. said method has the advantage of being carried out continuously or batchwise.