Abstract: Provided is a process for producing a plasticizer ester characterized by previously removing dissolved oxygen in a starting alcohol, and then subjecting an organic acid or its anhydride and the alcohol to an esterification reaction in the presence of an organic metal compound catalyst, which process can substantially reduce formation of coloring impurities and can easily provide a plasticizer ester having a low degree of coloring.Further, a plasticizer ester having a high volume resistivity can easily be obtained by adding an alkaline aqueous solution to a reaction product obtained by an esterification reaction to conduct neutralization of an unreacted acid and hydrolysis of the catalyst, further blowing a carbon dioxide gas to convert the residual alkali into a carbonate, recovering an excess alcohol, and then conducting purification through finefiltration using a filter aid or further in combination with adsorption treatment.

Abstract: A process for the production of esters, comprising allowing an olefin, carbon monoxide and an alcohol to react in the presence of hydrogen fluoride, in which the esters can be produced at high yields at a low temperature for a short period of time, the esters can be easily separated from a reaction solution, hydrogen fluoride can be recycled, the esters can be produced at a low cost, a mixture of esters can be easily produced, the kinetic viscosity of the mixture of the esters can be easily adjusted and the coloring of, and an increase in the viscosity of, the esters can be prevented.

Abstract: A process for producing an aromatic acylation product from an aromatic compound, an olefin and carbon monoxide, which comprises the steps of:(a) reacting an olefin with carbon monoxide in the presence of hydrogen fluoride and boron trifluoride at a pressure of not more than 100 kg/cm.sup.

Abstract: A process for manufacturing high-purity o-toluic acid from a partial oxidation product of o-xylene is disclosed. o-Toluic acid is widely used as a raw material for agricultural chemicals, medicines, polymerization initiators, and the like. Depending on its use, 99% by weight or more purity is demanded for o-toluic acid. Hitherto, o-toluic acid having purity of higher than 99% by weight could not be obtained by fractionation, and purification by fractional crystallization was used. Fractional crystallization is, however, and expensive operation and not only gives a low yield of product but also results a large amount of waste water. The process disclosed herein gives an economical, commercial way to obtain high purity o-toluic acid.

Abstract: The present invention relates to a process for decomposing an aromatic acylated compound.HF-BF.sub.3 complex in preparing an aromatic acylated compound by decomposing an aromatic acylated compound.HF-BF.sub.3 complex obtained by reacting an aromatic compound with an acylating agent in the presence of HF-BF.sub.3 as a catalyst, which comprises subjecting the aromatic acylated compound.HF-BF.sub.3 complex to thermal decomposition in the presence of at least one aromatic hydrocarbon (A.H.) selected from benzene, toluene and chlorobenzene and at least one saturated aliphatic hydrocarbon (S.H.) selected from pentane, hexane and cyclohexane, as a decomposing agent.