Abstract: A method of manufacturing .alpha.-oxocarboxylate includes the steps of: (i) carrying out a vapor phase oxidation of 1,2-diol of formula (1) in a primary reaction vessel, (ii) introducing a resulting gaseous .alpha.-oxoaldehyde and/or .alpha.-hydroxyaldehyde in a secondary reaction vessel together with alcohol or olefin which is converted into a gas form in a vaporizing chamber, and (iii) carrying out an oxidative esterification of the gaseous .alpha.-oxoaldehyde and/or .alpha.-hydroxyaldehyde molecular oxygen in a presence of inorganic oxide containing phosphorus as a catalyst in the secondary reaction vessel, ##STR1## (R is a hydrogen atom or an organic residue). The described method permits .alpha.-oxocarboxylate to be manufactured economically and effectively in practically one step using inexpensive 1,2-diol such as ethylene glycol or propylene glycol.

Abstract: A method of producing naphthalenedicarboxylic acids by the oxidation of dialkyl-substituted naphthalene with a gas containing molecular oxygen in an organic solvent and in the presence of a catalyst comprising copper and bromine, or a catalyst comprising copper, bromine and at least one kind of element/compound selected from the group of consisting of amine compounds and heavy metallic elements which are vanadium, manganese, iron, nickel, palladium and cerium. And a method of producing diaryldicarboxylic acids by the oxidation of dialkyl-substituted diaryl compounds with a gas containing molecular oxygen in an organic solvent and in the presence of the same catalyst. These methods permit high yields of naphthalenedicarboxylic acids of high purity and of diaryldicarboxylic acids of high purity with the use of small amounts of catalyst.

Abstract: A method of preparing alkylnaphthalene compounds by reaction of a compound of naphthalene or monoalkylnaphthalene with olefin in the presence of a heteropoly acid catalyst. The method enables to produce highly valuable 2-monosubstituted alkylnaphthalene compounds or 2,6-disubstituted alkylnaphthalene compounds, in a high selectivity and a high yield. The used catalyst may be readily recovered and re-utilized.

Abstract: A method of producing naphthalenedicarboxylic acids by the oxidation of dialkyl-substituted naphthalene with a gas containing molecular oxygen under liquid phase conditions in an organic solvent and in the presence of a catalyst comprising copper and bromine, or a catalyst comprising copper, bromine and at least one kind of element/compound selected from the group of consisting of amine compounds and heavy metallic elements which are vanadium, manganese, iron, cobalt, nickel, palladium and cerium. And a method of producing diaryldicarboxylic acids by the oxidation of dialkyl-substituted diaryl compounds with a gas containing molecular oxygen in an organic solvent and in the presence of the same catalyst. These methods permit high yields of naphthalenedicarboxylic acids of high purity and of diaryldicarboxylic acids of high purity with the use of small amounts of catalyst.