| 摘要 |
The parent Specification describes a process in which aromatic mononuclear compounds containing oxidizable side chains are oxidized to the corresponding carboxylic acids with nitric acid at a raised temperature and pressure, the reaction being effected in a vertical reactor through which the reagents flow upwardly and the reagents being mixed, at a temperature below the reaction temperature, before they enter the reactor, the arrangement being such that the speed of the mixture is decreased to at least one third as it enters the reactor. This process is now modified in that only 30-60% of the required nitric acid is supplied to the mixer, the remainder being supplied directly to the reactor at about the middle third. As in the parent Specification, the reaction may be effected at 150-400 DEG C. at 10-150 atm. pressure and optionally in the presence of the catalysts named in the parent Specification. Specified materials which may be oxidized are toluene, xylenes, cymene, diisopropylbenzenes, chlorotoluenes, nitrotoluenes, chloroxylenes, nitroxylenes, mesitylene, durene, toluic acids, benzyl chloride, xylylene dichlororide, chloromethylated xylenes, picolines and ethylpyridines. An example is given of the oxidation of p-xylene to terephthalic acid. |
