1,2-二苯肼的合成工艺改进

Research on the Synthesis of 1,2-Diphenylhydrazine

研究了硝基苯在强碱性介质中用锌粉还原制备 1 ,2 -二苯肼的反应。探讨了锌粉用量、溶剂的醇水体积比、溶剂总量对反应的影响。最佳反应条件为 :当硝基苯的用量为 0 .2 5 mol时 ,硝基苯与锌粉的摩尔比为 1∶ 5 ;溶剂的醇水体积比为 1∶ 1 .5 ,溶剂总量为 3 2 m L,反应时间为 1 .5 h,产率为 90 %。与文献[5] 比较 ,溶剂总量减少约 2 0 m L ,反应时间缩短 1 0 h以上 ,产率提高了

A new synthetic method of 1,2-diphenylhydrazine with nitro benzene and zinc powder in alkaline medium is reported. The volume ratio of ethanol to water, the consumption of zinc powder and solvent are studied. When the consumption of nitro benzene is 0.25 mol, the optimum molar ratio of nitro benzene to zinc powder is 1∶5, the consumption of solvent is 32 mL, and the volume ratio of ethanol to water is 1∶1.5. The reaction time (1.5 h) is 10 h shorten and the yield (90%)is 9% higher than in the literature [5].