6-溴-2,4-二硝基苯胺的绿色合成

Green synthesis of 6-bromo-2,4-dinitroaniline

以锌铝水滑石为载体,通过共沉淀法合成溴酸根插层的水滑石ZnAl-BrO_3^--LDHs,并采用XRD,FT-IR等手段对水滑石的结构进行了表征.溴酸根插层的锌铝水滑石作为氧化剂,KBr作为还原剂构建了溴源体系,在醋酸和水的混合溶剂中对2,4-二硝基苯胺进行氧化溴代合成,同时探究了投料比、温度和溶剂等因素的影响.得到目标产物6-溴-2,4-二硝基苯胺的最优条件:在n(2,4-二硝基苯胺)︰n(BrO_3^-)︰n(KBr)=1.0︰0.6︰0.6,溶剂为V(AcOH)︰V(H_2O)=9︰1,30℃条件下反应1h,6-溴-2,4-二硝基苯胺的收率为95%,纯度大于99%.该反应具有条件温和、溴原子利用率高和产物收率高等特点,是一种符合绿色化学的溴代方法.

The ZnAl-BrO--LDHswas synthesized with zinc aluminum hydrotalcite as the carrier via co-precipitation, and its structure was characterized by XRD and FT-IR. A new reagent system for bromination was builtwith the ZnAl-BrO--LDHs as oxidant and KBr as reductant in （AcOH/H2O） solvent, and the system was successfully applied for the oxidative bromination of2, 4-dinitroaniline. Futhermore, The effects of molar equivalent, temperature and solvent wereinvestigated. The optimization for synthesis of n（6-bromO-2,4-dinitroaniline） ： w（BrO-） ： n（KBr）= 1.0 ： 0.6 ： 0. 6,V（AcOH） ： V（H2O） = 9 ： 1 as solvent, temperature 300 for 1 h in 95% yield and a purity of 99%. This synthetic process was mild reaction conditions, high bromine atom utilization, in good yields and purity. it is a kind of bromine method which accords with the green chemistry.