250593-01-2Relevant academic research and scientific papers
Topramezone intermediate and topramezone preparation method
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Paragraph 0049; 0053-0055, (2020/04/06)
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.
