论文部分内容阅读
以1-溴-3-氯-5-氟苯为原料,分别经氰化、水解和霍夫曼降解反应合成标题化合物,含量为99.217%(HPLC),总物质的量产率为72%。其中,探索了霍夫曼降解反应的优化条件:n(3-氯-5-氟苯甲酰胺)∶n(氢氧化钠)∶n(溴素)=1.0∶4.0∶1.1,反应初期温度控制在0℃左右,后期缓慢升至回流温度后保温2 h。产物的结构通过MS及1HNMR验证。该法具有生产成本低廉、反应条件温和、易操作等特点,有利于工业化生产。
The title compound was synthesized from 1-bromo-3-chloro-5-fluorobenzene by cyanidation, hydrolysis and Huffman degradation respectively. The content of the title compound was 99.217% (HPLC) and the total mass yield was 72%. Among them, the optimum conditions of Huffman degradation reaction were explored: n (3-chloro-5-fluorobenzamide): n (sodium hydroxide) At about 0 ℃, the latter slowly rose to the reflux temperature after incubation 2 h. The structure of the product was verified by MS and 1H NMR. The method has the characteristics of low production cost, mild reaction conditions, easy operation and the like, which is beneficial to industrialized production.