?Optimization of the Hydrolysis Reaction Process in the Synthesis of 4-Aminoantipyrine by Response Surface Methodology and its Kinetics

In this paper, a unique hydrolysis reaction process for the production of 4-Aminoantipyrine (AA) is investigated. A liquid-phase analytical method for AA is established, and the amount of sulfuric acid, reaction temperature, reaction time are studied. On the basis of single factor experiments, the response surface method (RSM) is used to systematically optimize the conditions of the hydrolysis reaction. The optimum conditions are n(AT-SO4): n(H2SO4)=0.73, the reaction temperature is 98 degrees C, the reaction time is 91 min, and the AA yield reaches 90.80 %. Compared with the previous process, the yield of AA is improved and colloids are significantly reduced. Under optimum process conditions, a kinetic model is constructed in the range of 358 K-373 K, which activation energy, E-a=33.21 kJ/mol, and the pre-exponential factor, A=1586.84. In addition, the product AA is characterized by IR analysis, LC-MS analysis, GC-MS analysis and hydrolysis reaction mechanism are investigated.