Study On The Synthesis Of 4,4'-ethylenedianiline

4,4'-ethylenedianiline is an important intermediate in the synthesis of dyes,pharmaceuticals and polyurethane,it has many applications.In this paper,4,4'-ethylenedianiline is synthesized by two steps of oxidative coupling and catalytic hydrogenation,using p-nitrotoluene as raw material.At present,for the oxidative coupling reaction of p-nitrotoluene,oxygen or hydrogen peroxide is the oxidant,the yield is generally not high,side effects are serious,the selectivity is not good,moreover,synthesis of 4,4'-diaminobibenzyl is rarely reported by catalytic hydrogenation.Therefore,the study of increasing the yield of the oxidative coupling reaction of p-nitrotoluene,the study of increasing yields,reducing side reactions,and exploring the conditions of catalytic hydrogenation reactions are the subject of this paper.In this paper,the production process of oxidative coupling reaction and the effect of metal salt on the yield of 4,4'-dinitrodibenzyl are studied,and the reaction conditions for the synthesis of 4,4'-diaminobibenzyl catalyzed by Pd/C catalyst are studied.Reaction conditions are explored and optimized by orthogonal experiments and single-factor experiment,the optimum reaction conditions:the air flow rate is 2.5 L/min,the reaction temperature is between 20-25?,the molar ratio of p-nitrotoluene to potassium hydroxide is 1:2.5,and the solvent is DMSO,the yield is 75%.Experiment shows that the yield of 4,4'-dinitrodibenzyl exceeds 71%,and the selectivity exceeds 9%by using SnCl₂?BaSO₄?FeSO₄ as catalyst.The experiment of hydrogenation to prepare 4,4'-diaminobibenzyl show that the yield exceeds 90%,by using 1,4-dioxane as solvent,adding 20%Pd/C catalyst containing 5%palladium,at 60-90??In this paper,the innovation is to find the optimum production process of the oxidative coupling reaction,to find some suitable metal salt catalysts to improve the yield and selectivity of the oxidative coupling reaction,to find the reaction conditions for the synthesis of 4,4'-ethylenedianiline by hydrogenation?...