联苯吡菌胺关键中间体3′,4′-二氯-5-氟-1,1′-联苯-2-胺的合成

Synthesis of the key itermediate 3′,4′-dichloro-5-fluoro-1,1′-biphenyl-2-amine of bixafen

为获得联苯吡菌胺关键中间体3′,4′-二氯-5-氟-1,1′-联苯-2-胺的适合工业化生产工艺路线,对其合成工艺进行了优化。以3,4-二氯溴苯和2-溴-4-氟苯胺为原料,经格氏和Suzuki偶联2步反应合成了3′,4′-二氯-5-氟-1,1′-联苯-2-胺,其结构经1H NMR、MS表征确证,并对合成条件进行了优化。优化条件下,3′,4′-二氯-5-氟-1,1′-联苯2-胺合成总收率61.9%,纯度98%。该工艺成本低,收率高,具有工业化生产前景。

To obtain a new suitable industrial route of 3′,4′-dichloro-5-fluoro-1,1′-biphenyl-2-amine,which was the key intermediate of bixafen,the synthesis process was optimized.3′,4′-Dichloro-5-fluoro-1,1′-biphenyl-2-amine was synthesized using 3,4-dichlorobromobenzene and 2-bromo-4-fluoroaniline as starting material by two steps of grignard and Suzuki coupling reaction.The structure was confirmed by 1H NMR,MS,and the synthesis conditions were optimized.Under the optimal reaction conditions,the total yield of 4′-chloro-2-aminobiphenyl was over 61.9%based on 3,4-dichlorobromobenzene,the purity was 98%.This process has the feature of low cost,high yield and has the prospect of industrial scale manufacture.