A kind of production method of o-methylphenyl hydroxylamine

Abstract

The invention discloses a method for producing O-methyl phenyl hydroxylamine. The method comprises the following steps: adding ortho-nitrotoluene, a solvent and a catalyst to a reaction kettle, and stirring the materials, wherein the weight ratio of the ortho-nitrotoluene to the solvent to the catalyst is (35-45) to (80-150) to (5-6); then dropwise adding hydrazine hydrate at 0-8 DEG C, wherein the weight ratio of the hydrazine hydrate to the catalyst is (20-50) to (5-6); carrying out heat preservation reaction at 2-10 DEG C for 4-6 hours after dropwise adding is ended; removing the catalyst by suction filtration after cooling, standing and separating a water layer, and then removing the solvent by vacuum rotary evaporation; and recrystallizing the product by using petroleum ether, carrying out suction filtration and drying, so as to obtain the O-methyl phenyl hydroxylamine. The method disclosed by the invention has the advantages that reduction reaction is simple and easy to control, complicated hydrogenation device is not required, the cost is low, a raney nickel catalyst is adopted, and the reaction yield can be up to over 85%, and is much higher than that of normal process production, which is 70%.

Description

technical field [0001] The invention relates to the technical field of chemical materials, in particular to a production method of o-methylphenylhydroxylamine. Background technique [0002] The common name of pyraclostrobin is pyraclostrobin, the code name is BAS500F, the single-dose product names are Cabrio, Headline, Attitude, etc., the CAS registration number: 175013-18-0, and the chemical name is: N-{2-[1-(4 -Chlorophenyl)-1H-pyrazol-3-yloxymethyl]phenyl}(N-methoxy)amino acid methyl ester. The structural formula is: [0003] [0004] Pyraclostrobin is a broad-spectrum fungicide of the methyl methoxyacrylate category with a pyrazole structure discovered by BASF in 1993. It can prevent and control plant diseases caused by almost all types of fungal pathogens such as Ascomycetes, Basidiomycetes, Deuteromycetes and Oomycetes. At the same time, it is a hormone-type fungicide, which can make crops absorb more nitrogen , to promote the growth of crops. This variety is no...

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Problems solved by technology

[0010] Route 1, bromination of o-nitrotoluene requires N-bromosuccinimide (abbreviated as NBS), and o-nitrobenzyl bromide has high preparation cost, strong odor, strong lachrymatory property, and very low bromination yield , not conducive to large-scale industrial production

[0011] Route 2 has the advantages of readily available raw materials and significantly reduced costs, and is more conducive to intensive industrial-scale production in the future. However, the yield of o-nitrotoluene reduction to o-methylphenylhydroxylamine is low, currently the highest is less than 70%, which restricts application of this synthetic route

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