Patent GB-833438-A (GB)
Title: Oxidation of organic or carbonaceous substances
Inventor: MCINTYRE JAMES ERIC
IPC: C07B35/04
Filed: 1955-08-24
Abstract: Organic compounds or carbonaceous materials are oxidized to carboxylic acids, in a liquid medium which is stable under the oxidation conditions, by means of oxygen or a free oxygen-containing gas, by a process which comprises carrying out the oxidation in the presence of bromine or a bromine-containing substance.  A polyvalent metal oxidation catalyst may be present in the reaction mixture.  The processes of Specifications 807,091 and 810,020 are disclaimed.  The process may be carried out at atmospheric or superatmospheric pressure and at an elevated temperature.  The liquid medium is preferably one wherein the bromine or bromine-containing substance and the organic compound are at least slightly soluble.  Specified media are water and acetic or propionic acids.  Bromine may be used as such or preferably in the form of a compound, e.g. hydrogen bromide, a metallic bromide or an organic bromide.  The catalyst metals are present as oxides or preferably salts.  Preferred catalyst metals are vanadium, copper and manganese in aqueous media and cobalt and/or manganese in carboxylic acid media.  In examples: (1) p-toluic acid is oxidized to terephthalic acid with oxygen in aqueous medium in the presence of hydrogen bromide, ethyl bromide or sodium bromide and hydrogen chloride; (2) the following oxidations are carried out using oxygen and aqueous hydrogen bromide: o-toluic acid to phthalic acid, m-toluic acid to isophthalic acid, p-aldehydobenzoic acid to terephthalic acid, p-xylene to p-toluic and terephthalic acids, acetophenone to benzoic acid and p-diisopropylbenzene to terephthalic acid; (3) p-nitrotoluene and p-toluenesulphonic acid are oxidized to p-nitrobenzoic acid and p-sulphobenzoic acid by heating them in a sealed tube with aqueous hydrogen bromide and hydrogen peroxide; (4) gamma-picoline is oxidized in aqueous hydrogen bromide with oxygen to isonicotinic acid which is isolated as the copper salt; (5) charcoal is oxidized with oxygen and aqueous hydrogen bromide to humic acid and benzene polycarboxylic acids (isolated as the lead salts); (6) p-diisopropyl-benzene is oxidized to terephthalic acid in a sealed tube with aqueous hydrogen bromide, hydrogen peroxide and the following catalysts: ammonium vanadate, ferrous sulphate, copper acetate, copper and cobalt acetate, copper acetate and ferrous sulphate, ferrous sulphate and vanadium pentoxide, manganese acetate and vanadium pentoxide, cobalt acetate and vanadium pentoxide, ferrous sulphate and nickel sulphate; (7) using the method of (6), (a) acetophenone is oxidized to benzoic acid using ammonium vanadate as catalyst, and (b) ethyl- or isopropyl-benzene is oxidized to benzoic acid and cumic or a -hydroxycumic acids are oxidized to terephthalic acid using vanadium pentoxide as catalyst; (8) terephthalic acid is obtained by oxidizing with oxygen in aqueous medium (a) p-diisopropylbenzene in the presence of manganese, ferrous or copper bromides, or (b) p-diisopropylbenzene, cumic acid, a  - a 1-dihydroxy-diisopropylbenzene or p-diacetylbenzene in the presence of a mixture of manganese and copper bromides; (9) p-diisopropylbenzene is oxidized to terephthalic acid with oxygen in propionic acid medium in the presence of manganese acetate, cobalt nitrate and sodium bromide; (10) as in (9) but using cobalt acetate instead of cobalt nitrate, p-xylene, p-cymene, p-tolualdehyde and ptolunitrile are oxidized to terephthalic acid, 2 : 6-dimethylnaphthalene is oxidized to naphthalene-2 : 6-dicarboxylic acid, phenanthrene is oxidized to diphenic acid, m-xylene is oxidized to isophthalic acid, o-xylene is oxidized to phthalic acid and mesitylene to trimesic and uritic acids; (11) as in (10) but using acetic acid, p-xylylene dichloride is oxidized to terephthalic acid and p-chlorotoluene is oxidized to p-chlorobenzoic acid; (12) p-xylene is oxidized to terephthalic acid as in (10) but using cobalt and manganese bromides instead of the salts specified in (10); (13) p-xylene is oxidized to terephthalic acid as in (10) but the sodium bromide is replaced by bromine, pxylylene dibromide or bromoacetic acid; (14) p-xylene is oxidized to terephthalic acid with oxygen in propionic acid in the presence of manganese and cobalt bromides, cobalt bromide or cobalt acetate and sodium bromide; (15) as in (14) acetophenone is oxidized to benzoic acid in the presence of manganese bromide, or manganese acetate and sodium bromide; (16) p-diisopropylbenzene is oxidized to terephthalic acid with oxygen in aqueous propionic acid in the presence of sodium bromide and vanadium pentoxide; (17) p-xylene is oxidized to terephthalic acid with oxygen in molten benzoic acid in the presence of manganese and cobalt bromides.  In many of the examples the results obtained when the bromine-containing substance and/or the metal catalyst are not present are specified.  Specifications 24662/1907 and 735,885 also are referred to.