Clean production method to oxidize 3-nitro-o-xylene into 2-methyl-3-nitrobenzoic acid

Abstract

The invention discloses a clean production method to oxidize 3-nitro-o-xylene into 2-methyl-3-nitrobenzoic acid. The clean production method comprises the steps of adding 3-nitro-o-xylene with an acidinto an organic solvent under the action of a catalyst, adding an oxidant, and stirring to allow reacting to obtain 2-methyl-3-nitrobenzoic acid, wherein the oxidant is hydrogen peroxide, and the catalyst is a transition metal compound. The hydrogen peroxide is used herein as a clean oxidant, so that the oxidants, such as potassium permanganate, causing high environmental pollution are avoided. The reaction system is mild; post-reaction treatment is simple and practical; reaction selectivity is good; few byproducts are produced; the target product is easy to purify; both the yield and purityare high; the cost is low; the clean production method has a good industrial application prospect.

Description

Technical field [0001] The invention relates to a clean production method for oxidizing 3-nitro-o-xylene to 2-methyl-3-nitrobenzoic acid. Background technique [0002] Methoxyfenozide is a new type of specific low-toxic benzohydrazide insecticide. It has high selective insecticidal activity against lepidopteran pests, mainly contact killing, and has a certain systemic effect. The drug belongs to the biomimetic ecdysone class. After the pests take the drug, they will have a molting reaction and begin to molt. The larvae are dehydrated, starved and die due to inability to completely molt. The mechanism of the drug is opposite to that of the drug that inhibits moulting of pests. It can be used for prevention and control of pests throughout the larval stage. [0003] 2-Methyl-3-nitrobenzoic acid is used as the intermediate of methoxenozide. It has been reported in the literature that 3-nitro-o-xylene can be oxidized by dilute nitric acid, potassium permanganate, oxygen, and other oxid...

AI Technical Summary

Problems solved by technology

Among them, the nitric acid oxidation method is the main method of industrial production at present, but dilute nitric acid oxidation needs to be carried out under the condition of high temperature and high pressure, which is dangerous and has major safety hazards, and there is also serious pollution of low-concentration nitric acid wastewater, and by-products 2- There are many problems such as methyl-6-nitrobenzoic acid; the method of using potassium permanganate as the oxidant, the oxidant potassium permanganate meets ammonium salt, contacts or mixes with organic matter, reducing agent, combustibles such as sulfur, phosphorus, etc. Sometimes there is a danger of burning and explosion, and the reduction product of potassium permanganate will cause a large amount of solid waste such as potassium manganate in the production process, causing serious harm to the environment and ecology; the oxygen oxidation method has been reported, and it exists in the actual production process There are many potential safety hazards, and the technical process is difficult to implement on a large scale.

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