| 摘要 |
PURPOSE:To obtain 2,4-dichlorobenzoic acid useful as an intermediate for agricultural chemicals, medicines, etc., in high yield and high purity, industrially, by the liquid-phase oxidation of 2,4-dichlorotoluene using a catalyst containing cobalt, manganese and bromine. CONSTITUTION:2,4-Dichlorobenzoic acid is obtained in high purity and high yield, by the liquid-phase oxidation of 2,4-dichlorotoluene with a gas containing molecular oxygen, such as pure oxygen or air, in a lower fatty acid such as acetic acid, or its anhydride, preferably at 100-220 deg.C, especially at 130-200 deg.C, in the presence of a catalyst containing CO, Mn and Br, wherein at least one of the CO and Mn is contained as a bromide and the other is contained as a salt of an organic acid, such as acetic acid, or as a complex salt, such as an acetylacetonate. The preferable ratios of Co:Mn:Br are 1:0.1-3, especially 0.3-2:2-15 (weight ratio). The amount of the catalyst used is preferably 0.05-3wt% based on 2,4-dichlorotoluene. |
