Study On The Process For Synthesis Of4-Amino-N-(4-Aminophenyl) Benzene Sulfonamide

4-Amino-N-(4-aminophenyl) benzene sulfonamide is one of the important intermediates and a substitute of benzidine in the synthesis of fine chemicals and dyes. This intermediate can be used as the coupling component for azo dye synthesis, such as active dyes, acid dyes and so on.Base on evaluation of several synthetic routes in known literature, the route starting from p-nitroaniline and acetanilide was studied in the thesis.4-Amino-N-(4-aminophenyl) benzene sulfonamide was synthesized by hydrolysis of the product condensed between p-phenylenediamine and p-acetanmidobenzenesulfonylchloride. p-Phenylenediamine was synthesized by reduction of p-nitroaniline, and p-acetanmidobenzenesulfonylchloride was synthesized by chlorosulfonation of acetanilide.The reduction of p-nitroaniline was studied and the amount of iron powder was main factor influencing the reduction. Chlorosulfonation reaction was investigated by changing the amount of chlorosulfonic acid and adding sulfoxide chloride or phosphorus pentoxide and the yield can be increased to91.6%through the addition of phosphorus pentoxide. The influencing factors such as pH, reaction temperature and reactant molar ratio on the yields was studied in condensation reaction, and through the orthogonal optimization the optimum parameters of the process were selected as follows:pH is7.7to8.0, temperature is35℃and reactant molar ratio is1:1.3. In order to recover the excess p-phenylenediamine, wastewater was recycled3times. The optimal of the amount of sodium hydroxide was evaluated in hydrolysis reaction and the wastewater can be reused3times.According to the demand of market and the company, the process for600t/y of4-amino-N-(4-aminophenyl) benzene sulfonamide was designed combined with the optimized process data. The layouts of production workshop and the process flow diagram were determined. The process equipments were designed and selected. The technical and economic feasibility was evaluated and it provided a good theoretical guidance for the industrialization promotion and process optimization in the future.