GB824116A - Process for the oxidation of organic compounds - Google Patents

Abstract

Driers for drying oils and varnishes comprise a bromide of at least one metal of variable valency. Linoxyn may be obtained by oxidizing linseed oil with molecular oxygen or ozone in liquid phase in the presence of such a catalyst. Manganese and cobalt bromides, preferably a mixture of the two are the preferred catalysts; a mixture of lead and manganese bromides may also be used. The bromides are preferably introduced as such, but may be produced in situ by using salts of the metal soluble in the reaction mixture, e.g. acetates or naphthenates, and introducing, e.g. bromine, hydrobromic acid or an alkali metal bromide. The catalytic metal may also be introduced as reduced metal, as carbonyl or as oxide.ALSO:Oxygen-containing organic compounds are prepared by oxidizing aliphatic or alicyclic compounds with molecular oxygen or ozone in the liquid phase in the presence of a catalyst comprising the bromide of a metal of variable valency. The molecular oxygen may be fed as such or as air or diluted air or may be produced in situ, e.g. by the decomposition of a compound such as hydrogen peroxide which under the reaction conditions decomposes in the presence of the metal catalyst to yield oxygen. Manganese and cobalt bromides, preferably a mixture of the two are the preferred catalysts, but a mixture of lead and manganese bromides may also be used. Suitable proportions of catalyst are from 1 to 0.0005 gram atoms of total metal per gram mol. of starting material. The ratio of manganese to cobalt is preferably about 2 : 1, although up to about 9 : 1 gives good results. Solvents may be used such as C1-6 aliphatic carboxylic acids, aromatic hydrocarbons, halogen derivatives of benzene, aromatic acids and water or homogeneous mixtures thereof. Substances which may be oxidized include aliphatic or alicyclic hydrocarbons and their halogenated derivatives, e.g. cyclohexene and cyclohexane to adipic acid, methyl cyclohexene and methyl cyclohexane to, into alia, glutaric and succinic acids, paraffins such as pentane which gives butyric, propionic, acetic and formic acids; saturated aliphatic aldehydes to the corresponding acid, halogenated aldehydes; ketones to the corresponding acid, e.g. cyclohexanone to adipic acid; ethers to carboxylic acids, frequently accompanied by the corresponding ester, e.g. b ,b 1-dichlorodiethyl ether to b -chloroethyl chloroacetate and chloracetic acid and diethyl ether to ethyl acetate and acetic acid. The process may be operated batchwise, e.g. at temperatures up to 300 DEG C. and pressure up to 200 atmospheres, or continuously. A plurality of stages may be used, fresh catalyst being introduced in each stage. The bromides are preferably introduced as such, but may be produced in situ by using salts of the metals which are soluble in the reaction mixture, e.g. acetates or naphthenates, and introducing, e.g. bromine, hydrobromic acid or an alkali metal bromide. Bromine may be introduced in the oxygen stream. The catalytic metal may also be introduced as reduced metal, as carbonyl or as oxide. The bromine lost during the process may be replaced by introducing bromine, hydrogen bromide or a bromo derivative of the aromatic starting material. The proportion of bromine may be more than, less than, or equal to that equivalent to the metal of variable valency. In examples, mixtures of cobaltous bromide and manganese dibromide are used to catalyse the oxidation with oxygen of: (1) n-butyraldehyde to n-butyric acid; (2) isobutyraldehyde to isobutyric acid; (3) cyclohexanone in aqueous acetic acid to adipic acid; and (5) methylcyclohexanone in anhydrous propionic acid to succinic anhydride and glutaric acid. Specifications 738,808 and 777,010 are referred to.ALSO:Driers for alkyd resins comprise a bromide of at least one metal of variable valency. Cobalt bromide is used in Example 4 in an alkyd resin varnish. Manganese and lead bromides are also mentioned. The bromides may be introduced as such or may be formed in situ, by using compounds of the catalytic metal, e.g. salts, oxides, carbonyls or reduced metal, and introducing, e.g. bromine, hydrobromic acid or alkali metal bromide.