| 摘要 |
1344383 Preparation of mono- and dimethylterephthalate DYNAMIT NOBEL AG 19 April 1971 [4 March 1970] 22835/71 Heading C2C Dimethyl terephthalate is obtained by air oxidation of substantially methanol-free pxylene/methyl p-toluate mixtures, esterification of the acids formed and return of the methyl p-toluate for oxidation, wherein a combination of cobalt and manganese compounds is used as oxidation catalyst. The invention also provides a method for producing p-toluic acid and monomethyl terephthalate which comprises subjecting to aerial oxidation, in the liquid phase, a substantially methanol free mixture containing p-xylene and methyl p-toluate at an elevated temperature in the presence of an oxidation catalyst which comprises a manganese compound and a cobalt compound which are soluble in the reaction system. |
