Synthetic Process Study Of2,2’-(ethylenedioxy)dianiline

2,2’-(Ethylenedioxy)dianiline is an important chemical intermediate, it has a very wide range of applications in the field of medicine, dye pigments, inks and pesticides pharmaceuticals, which mainly used in synthesizing high-grade organic dye C.I.Pigment Yellow 180. In addition, it can be used in preparating the calcium ion sensor of the bisaminophenol tetraacetic(BAPTA) precursor.Along with Pigment Yellow 180 continuously expanding the scope of application,2,2’-(Ethylenedioxy)dianiline is used for intermediates of Pigment Yellow 180. The exploration and discovery a mature and feasible synthesis process of which can not only obtain great social benefits but also generate considerable economic benefits. Thus to explore a route with a high purity and high yield is of great significance. But so far, research on this area in general have had high cost, harsh conditions during synthesis, it is difficult to achieve large-scale industrial production. In response to these deficiencies,based on the analysis of the existing synthetic route and after many experiments, this paper develops a process suitable for industrial production. The improved process is mainly inexpensive and readily available o-dichlorobenzene as the starting material, by O-alkylation reaction and reduction reaction producing 2,2’-Diamino-glycol ether. The main findings are as follows:(1)Synthesis of 1,2-Bis(2-nitrophenoxy)ethane. O-dichlorobenzene and ethylene glycol as the raw materials carried out O-alkylation reaction, in the presence of a phase transfer catalyst and alkaline conditions. Reaction process was optimized to determine the ideal conditions: the reaction temperature is 88℃, the catalyst is benzyl triethyl ammonium chloride,the concentration of sodium hydroxide solution is 44%, the reaction time was 15 hours, the yield increased from 63% to 85%. In addition, we also studied the reaction wastewater.Wastewater is also a large amount of sodium o-nitro phenol, acidified to precipitate, and then through the steam distillation method further obtain high purity o-nitrophenol.( 2) Synthesis of 2,2’-(Ethylenedioxy)dianiline. The paper compares three different reduction methods, which screened out the best method for the catalytic hydrogenation reduction. And the influence factors of the reaction that is the temperature the reaction pressure, amount of catalyst, the amount of solvent were optimized. And ultimately theoptimal reaction conditions are determined: reaction pressure is 0.4MPa, the reaction temperature is 70 ℃, catalyst dosage is 3%, the solvent is ethanol, the amount of solvent is70 m L. The improved process reaction yield increased from 89% to 96%.( 3) Based on the synthesis of 2,2’-(Ethylenedioxy)dianiline small scale process optimization, the product is carried out the pilot study and design related process flow schematic diagram and operation procedures, product analysis and detection methods, pilot obtained qualified products, and reached small scale result, to the process of industrialization provide a strong support.This article selected process route has the advantage of low production cost, simple process operation, high yield, good purity and environment-friendly, the process is suitable for industrial production.