Green Synthesis Of 3-aminobenzenesulfonic Acid And The Establishment Of Quality Control Method

3-Aminobenzenesulfonic acid is an important chemical intermediate,mainly used in dyes,pharmaceuticals,pesticides and optical materials,etc.In the traditional preparation method,sodium 3-nitrobenzenesulfonate is reduced by iron powder and acidified.But products of this method are of poor quality and pollution is serious.Electrochemical synthesis can be used to reduce sodium 3-nitrobenzenesulfonate.But the power consumption is very large and the cost is high.Catalytic hydrogenation method has the advantages of less pollution and high product quality,so it is a better production process.Catalytic hydrogenation method is a better reduction method,the skeleton nickel catalyst and supported nickel catalyst are both good catalytic hydrogenation catalysts,and it is a hot topic in today’s research,and it is also widely used in various hydrogenation reactions.Quality control method of 3-Aminobenzenesulfonic acid is set up.By using Waters 2695-2996 high performance liquid chromatograph,the chromatographic condition is established.The column is waters Atlantis C18 column（4.6 mm×150 mm,5.0μm）.The mobile phase is potassium dihydrogan phosphate solution:methanol=9:1.The concentration of potassium dihydrogan phosphate solution is 20 m mol/L.And the pH is 3.5.The detection wavelength is 220 nm.The flow rate is 1ml/min.The column temperature is 25 degrees.This test method is verified,and the results show that this method meets the requirements.The self-made Raney nickel catalyst is used in the hydrogenation of sodium 3-nitrobenzenesulfonate reduction,and we optimize the process conditions,determine that the amount of catalyst is 3%（relative to the amount of sodium 3-nitrobenzenesulfonate）,the reaction temperature is100 degrees Celsius,the reaction pressure is 2.0MPa,the reaction time is2 hours,the conversion rate is 100%.The stability of the catalyst is studied,and the results show that the catalyst effect does not decrease obviously after 11 repetitions.The effects of catalyst type,loading dosage,roasting temperature and time,reduction temperature,reduction time are detected of the supported nickel catalyst.And we optimize the process conditions,determine that the carrier is silicon oxide,the load is 35%,roast at 400degrees for 2 hours and reduce at 450 degrees for 1 hour.The hydrogenation of the supported nickel catalyst under the optimal conditions is applied in sodium 3-nitrobenzenesulfonate reduction reaction,we detect the effects of catalyst dosage,reduction temperature,reduction of pressure and determine the optimal conditions.The catalyst amount is 10%（relative to the amount of sodium3-nitrobenzenesulfonate）,the temperature is 80 degrees,the reducing pressure is 2.0MPa.Under this condition,the reaction is finished in 75minutes.The kinetics of the reaction is studied.The activation energy of the reaction is 49.42 kJ·mol and pre exponential factor is 3.41×10⁵mol·L^-1·min^-1.The stability of the catalyst is investigated,but the effect of repeated use of the catalyst is not ideal.