5-硝基水杨醛分离纯化方法改良

对 5 硝基水杨醛的分离提纯方法进行了改良研究 ,发现加入一定量的稀碱使 3 和 5 硝基水杨醛均完全转变成钠盐是实验成功的关键。进而利用两种钠盐在水中溶解度的差异 ,采用水抽提方法 ,先将 3 和 5 硝基水杨醛的钠盐以溶液形式分离开 ,再分别经酸化及重结晶处理 ,即得产率为 5 8 0 %的 5 硝基水杨醛 ,纯度经HPLC测定为 99 4 % ,其结构经元素分析、红外、紫外、核磁等确证。同时还得到产率为 35 0 %的 3 硝基水杨醛。

Improvement on the Separation and Purification of 5-Nitrosalicylaldehyde

The separation and purification method of 5 nitrosalicylaldehyde was studied.The key step was that 3 and 5 nitrosalicylaldehydes were both completely changed into their sodium salts through addition of appropriate amount of diluted sodium hydroxide solution.According to the solubility difference of 3 and 5 nitrosalicylaldehyde sodium salts in water,the sodium salt of 3 and 5 nitrosalicylaldehydes are firstly separated by extration with water.Then their sodium salt solutions were acidfied and recrystallized separately.5 Nitrosalicylaldehyde was obtained in 58 0% yield and the purity was 99 4% as determined by HPLC.Its structure was identified by elementary analysis,IR,UV and 1HNMR.At the same time,3 nitrosalicylaldehyde was obtained in 35 0% yield.