5-氨基-6-氯苯并咪唑酮的合成工艺研究

Study on the Synthesis of 5-amino-6-chlorobenzimidazolone

介绍了苯并咪唑酮类颜料和染料中间体5-氨基-6-氯苯并咪唑酮的合成路线。讨论了硝基还原方法、硝化方法以及苯并咪唑酮类化合物的合成方法。通过正交实验得到了环合反应的最佳条件(溶剂:甲苯,4-氯邻苯二胺与三光气的摩尔比为1.0∶0.4,反应温度80℃);通过单因素试验得到了硝化反应的最佳条件(5-氯苯并咪唑酮与硝酸的摩尔比为1.0∶1.2,反应温度40~45℃)和还原反应的最佳条件(溶剂:乙醇,5-硝基-6-氯苯并咪唑酮与水合肼的摩尔比为1.0∶2.2)。优化后,四步反应的的总收率为60.0%,产品液相色谱含量99.2%。

The synthetic route of benzimidazolidone pigments and dye intermediate 5-amino-6- chlorobenzimidazolone was introduced. The methods of nitro reduction, nitration and synthesis of benzimidazolidone compounds were discussed. The cyclization reaction conditions were obtained by orthogonal experiments (the solvent was toluene, the mole ratio of 4-chloro-o-phenylenediamine to triphosgene was 1.0∶0.4, the reaction temperature was 80℃). The optimum conditions of nitration (the mole ratio of 5-chlorobenzimidazolone to nitric acid was 1.0∶1.2, the reaction temperature was 40~45℃) and reduction (the solvent was ethanol, the mole ratio of 6-chloro-5-nitrobenzimidazolone to hydrazine hydrate was 1.0∶2.2) were obtained by single factor experiments. After optimization, the total yield of the four-steps was 60.0% with the purity 99.2%.