吡啶氮氧化物衍生物的合成

Synthesis of Pyridine N-Oxides Derivatives

以2,3-二甲基吡啶为起始物,利用双氧水为氧化剂在催化剂钨酸钠的作用下进行氧化,以溴素为溴代试剂在水中溴代,最后与甲醇钠在甲醇中反应得到了一种拉唑类中间体:2,3-二甲基-4-甲氧基-吡啶-N-氧化物。通过核磁、质谱以及高效液相对产物结构进行了表征和分析,通过工艺优化得到了较纯的产物和较高的收率,总收率为84.7%,HPLC纯度99%。该路线避开了较为危险的硝化反应,减少了反应步骤,收率高,操作简单,有利于工业化生产。

In this paper,2,3-dimethylpyridine was used as the starting material, hydrogen peroxide as the oxidant to oxidize under the action of the catalyst sodium tungstate, bromine as the bromine reagent in water, and finally reacted with sodium methoxide in methanol to obtain a kind of prazole intermediate :2,3-dimethyl-4-methoxy-pyridine-N-oxide. The structure of the product was characterized and analyzed by nuclear magnetic resonance, mass spectrometry and HPLC. The pure product and higher yield were obtained by process optimization, the total yield was 84.7 % and the HPLC purity was 99 %. This route avoids the dangerous nitrification reaction, reduces the reaction steps, has high yield, simple operation, and is beneficial to industrial production.