噻菌灵的合成工艺研究

Synthesis of Thiabendazole

噻菌灵是一种高效、广谱性杀菌剂,在农业领域有广泛应用。介绍了改进的噻菌灵合成工艺,以2-（1-羟乙基）苯并咪唑为原料,在磷钨杂多酸存在下用H_2O_2催化氧化得到2-乙酰基苯并咪唑,再经溴素卤化得到1-（1H-苯并咪唑-2-基）-2-溴乙酮,最后与硫代甲酰胺合环得到2-（4-噻唑基）-1H-苯并咪唑,即目标化合物,总收率为67.9%,HPLC纯度为98.1%。其化学结构经^1HNMR分析得到确证。

Thiabendazole has wide application as an efficient,broad-spectrum fungicide in the field of agriculture. In this work,the improved synthetic processes were introduced. Firstly,in the presence of H_2O_2 and at action of catalyst of phosphotungstic acid,2-（ 1-hydroxyethyl） benzimidazole was oxidized to obtain the intermediate product of 2-acetylbenzimidazole,then 2-acetylbenzimidazole could react with bromine by halogenation to obtain 1-（ 1H-benzimidazol-2-yl）-2-bromoethanone. Finally,under the cyclization of thioformamide,thiabendazole was obtained. Under the optimum conditions,the yield of thiabendazole reached to 67. 9%,purity was 98. 1%. The chemical structures of all compounds were confirmed by their ^1HNMR data.