Glyphosate Synthesis Process Optimization

In this thesis a three step synthetic procedure of glyphosate was studied. The dehydrogenation of diethanolamine led to iminodiacetic acid, which reacted with phosphorus trichloride to provide PMIDA. The oxidation of PMIDA led to glyphosate. For the dehydrogenation step, the reaction factors, including reaction temperature, pressure, dosage of catalyst and the ratios of various reaction materials, were optimized. Meanwhile, the successive dehydrogenation procedure was also studied. The product yield reached95%.In the synthesis of PMIDA, factors, such as the sequence of the ratio of material, the time for the aldehyde addition and the reaction temperature and period were optimized and94%of PMIDA was obtained under optimized conditions. The reaction procedure was stable and easy to handle. The continuous procedure for PMIDA synthesis was also investigated.In the final step, the glyphosate synthesis step, optimization of reaction factors was also carried out. It was showed that, under optimal reaction conditions, solid glyphosate was obtained in92%yield with97%purity. Meanwhile, a method of detecting the concentration of tail oxigen was developed and used successfully to determine the finishing point of the reaction. The small-scale and mid-scale production results showed that the method can make the judgment of the end point of reaction quickly and accurately.