Patent GB-725375-A (GB)
Title: Process for the oxidation of organic compounds
IPC: C07C31/20
Filed: 1953-05-04
Abstract: In the oxidation of an organic compound with a peroxide in the presence of tungstic acid catalyst, the reaction mixture is treated with a water-soluble salt to separate tungstic acid therefrom.  Salts having polyvalent anions or cations are preferred, for example, calcium chloride, barium acetate, magnesium nitrate, ferric chloride, vanadyl sulphate, sodium sulphate, potassium phosphate, and ferrous ammonium sulphate; salts of chromium, manganese, cobalt, nickel, copper, and zinc, and vanadates, sulphites and formates are also mentioned.  A suitable temperature for treatment is between 50 DEG and 100 DEG  C. About 1-6 per cent by weight of the salt, based on the tungstic acid present, is added in the form of a 5-20 per cent aqueous solution.  A flow sheet illustrates the oxidation of allyl alcohol with aqueous hydrogen peroxide to form glycerol; reaction takes place in two stages, the first at 40-60 DEG  C. and the second at 60-100 DEG  C.  The salt is added during the second stage and tungstic acid coagulates and is removed by centrifuging and re-used in the process; the product containing glycerol is distilled to remove excess allyl alcohol and then passed through beds of cation and anion exchange material to remove dissolved tunstic acid and the water soluble salt.  The caustic soda solution used to regenerate the anion exchange bed is treated with hydrochloric acid and a salt to recover more tungstic acid. Examples describe also the formation of glycerol monochlorhydrin from allyl alcohol, hydrochloric acid and hydrogen peroxide; dodecanones from propylene tetramer and an acetic acid solution of hydrogen peroxide; and epsilon-acetoxy-caproic acid and ethyl-epsilonhydroxycaproate from cyclohexanone and an acetic acid solution of hydrogen peroxide.  Reference is also made to the oxidation of methyl vinyl carbinol to alphamethyl glycerol, methallyl alcohol to beta-methyl glycerol, propylene to propylene glycol, cyclo-hexene to 1,2-cyclohexanediol, crotonic acid to alpha, beta-dihydroxybutyric acid, maleic acid to tartaric acid, vinyl ethers or esters to glycolaldehyde, and allyl ethyl ether and diallyl ethers to polyhydroxy ethers.  Reference has been directed by the Comptroller to Specification 654,764.ALSO:In the oxidation of an organic compound with a peroxide in the presence of tungstic acid catalyst, the reaction mixture is treated with a water-soluble salt to separate tungstic acid therefrom.  Salts having polyvalent anions or cations are preferred, for example, calcium chloride, barium acetate, magnesium nitrate, ferric chloride, vanadyl sulphate, sodium sulphate, potassium phosphate, and ferrous ammonium sulphate; salts of chromium, manganese, cobalt, nickel, copper, and zinc, and vanadates, sulphites and formates are also mentioned.  A suitable temperature for treatment is between 50 DEG  and 100 DEG  C. About 1-6 per cent. by weight of the salt, based on the tungstic acid present, is added in the form of a 5-20 per cent. aqueous solution. A flow sheet illustrates the oxidation of allyl alcohol with aqueous hydrogen peroxide to form glycerol; reaction takes place in two stages, the first at 40 DEG -60 DEG  C. and the second at 60 DEG -100 DEG  C.  The salt is added during the second stage and tungstic acid coagulates and is removed by centrifuging and re-used in the process; the product containing glycerol is distilled to remove excess allyl alcohol and then passed through beds of cation and anion exchange material to remove dissolved tungstic acid and the water-soluble salt.  The caustic soda solution used to regenerate the anion exchange bed is treated with hydrochloric acid and a salt to recover more tungstic acid.  Reference has been directed by the Comptroller to Specification 654,764 [Group IV (b)]