5-甲氧基-2-巯基苯并咪唑合成新工艺

对以２ 硝基 ４ 甲氧基苯胺为原料合成５ 甲氧基 ２ 巯基苯并咪唑的工艺进行了如下改进：（１）将两步反应合并为“一锅炒”工艺，不需分离易氧化的中间体对 甲氧基邻苯二胺，革除了高真空蒸馏工艺；（２）环合时，用聚乙二醇催化，以水代乙醇作溶剂，变回流反应为（３０±５）℃保温反应，降低了成本。总收率７２％，比原分步工艺高１６％，目标产品纯化不需柱层析。

A New Process for Synthesis of 5-Methoxy-2-mercaptobenzimidazole

The synthesis of 5methoxy2mercaptobenzimidazole from o nitro p methoxyaniline was improved as follows: (1) As the original twostep reaction was completed in one reactor, the very oxidizable p methoxy o benzenediamine needn't be isolated. The high vacuum distillation was avoided. (2) In the last reaction, the reaction condition was changed to keep warm at (305) from refluxing and using water as solvent instead of alcohol, using the polyglycol ether as catalyst.The total yield was 72%,and 16% higher than the original reactions. The product can be purified without colum chromatograph.