128277-66-7

Upstream product

• 22364-25-6 4-bromo-2,3-dimethylaniline 
• 250593-00-1 2,3-dimethyl-4-methylsulfanylbromobenzene 
• 87-59-2 2,3-Dimethylaniline 
• 66794-10-3 1,2-dimethyl-3-(methylsulfanyl)benzene 

Downstream Products

• 210631-68-8 topramezone 
• 247922-29-8 3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole 

Relevant academic research and scientific papers

The Synthesis and Crystal Structure of a Novel Pesticide Intermediates

A novel pesticide intermediates 3-(6-bromo-2-methyl-3-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole was synthesized with 2,3-dimethylaniline as the starting materials. The final product and intermediates were characterized by mass spectra, 1H NMR, infrared and elemental analysis. The crystal structure of compounds 6 and 8 were determined by single crystal X-ray diffraction. Results shown that two oxazole compounds crystallize in the monoclinic (6) and triclinic (8) with the space group of P 21/c for 6 and P-1 for 8, respectively.

Synthesis method of topramezone key intermediate

The invention discloses a green synthesis method of a herbicide topramezone key intermediate 2,3-dimethyl-4-methanesulfonyl bromobenzene (I), which comprises the following steps: in DMSO, directly carrying out a methanesulfonylation reaction on 4-halogena

Preparation method of 3-[3-bromo-2-methyl-6-(methylsulfonyl) phenyl]-4, 5-dihydroisoxazole

The invention belongs to the field of chemical synthesis, the invention relates to a preparation method of 3-[3-bromo-2-methyl-6-(methylsulfonyl) phenyl]-4, 5 -dihydroisoxazole. The 3-[3-bromo-2-methyl-6-(methylsulfonyl) phenyl]-4, 5 -dihydroisoxazole is prepared by taking 2, 3-dimethylaniline as an initial raw material for reaction. The method comprises the following steps: diazotizing, brominating and oximating the 2, 3-dimethylaniline to obtain an oximated product, and is mainly characterized in that the oximated product is oxidized by a one-pot method, and then subjected to isoxazole cyclization to obtain the target product. The method has the advantages that monopoly of a traditional route is broken through in the last two steps, and the method is safe, environmentally friendly, easyto industrialize and promising in market prospect.

Topramezone intermediate and topramezone preparation method

The invention relates to the field of organic synthesis, in particular to a topramezone intermediate and a topramezone preparation method. The topramezone preparation method comprises the following steps: 3-[3-halogen-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole and cyanide are subjected to a substitution reaction to obtain 3-[3-cyano-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole; hydrolysis reaction is performed on 3-[3-cyano-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole under the action of acid or alkali to obtain 2-methyl-3-(4, 5-dihydroisoxazole-3-yl)-4-methylsulfonyl benzoic acid; and 2-methyl-3-(4, 5-dihydroisoxazole-3-yl)-4-methylsulfonyl benzoic acid and 1-methyl-5-hydroxypyrazole are condensed and rearranged to generate topramezone. According to the topramezone intermediate and the topramezone preparation method provided by the invention, the use of an expensive palladium catalyst and a dangerous butyl lithium reagent is avoided, the yield isrelatively high, the cost is reduced, the process is simplified, the defects in the prior art are overcome, and the industrial value is achieved.

Preparation method of topramezone intermediate

The invention relates to a preparation method of a topramezone intermediate, which comprises the following steps: reacting 2,3-dimethyl diphenyl sulfide, hydrobromic acid and hydrogen peroxide in a solvent in the presence of a catalyst to obtain 2,3-dimet

Synthesis method and application of topramezone impurity

The invention discloses a synthesis method of topramezone impurity. The method includes: taking 2, 3-dimethylaniline as the starting raw material, carrying out methyl sulfidation, bromination, oxidation, oximation and chlorination ring-closing to synthesize 3-[3-bromo-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole, and carrying out condensation with 1-methyl-5-hydroxypyrazole under an alkaline condition to synthesize 3-[2-methyl-3-(1-methyl-1H-pyrazole-5-oxyl)-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole. The invention also discloses application of the corresponding product. The synthesis method provided by the invention has the characteristics of simple operation, easily control process, and a product yield of 40%-80%. The obtained product can be used as a standard substancefor detecting and monitoring the synthesis of topramezone.

Method and novel intermediate products for producing isoxazolin-3-yl-acylbenzenenes

The present invention describes a process for preparing isoxazoles of the formula I where: R1is hydrogen, C1-C6-alkyl, R2is hydrogen, C1-C6-alkyl, R3, R4, R5are each hydrogen, C1-C6-alkyl or R4and R5together from a bond, R6is a heterocysclic ring, n is 0, 1 or 2; which comprises preparing an intermediate of the formula VI where R1, R3, R4and R5are each as defined above, followed by halogenation, thiomethylation, oxidation and acylation to give compounds of the formula I. Furthermore, the invention describes novel intermediates for preparing the compounds of the formula I and novel processes for preparing the intermediates.