Study On The Process And Mechanism Of Aromatic Aldehyde Preparation Via Liquid Autoxidation Of Mono-substituted Toluene

As a clean and relatively cheap oxidant, dioxygen/air receives more and more interest. In this dissertation, it is discussed that the preparation of aromatic aldehyde via liquid autoxidation of mono-substituted toluene. It is showed that under optimum condition, the yield of p-chlorobenzaldehyde is 20% of 28% via air or dioxygen oxidation under ordinary pressure, 34% under 0.3Mpa via dioxygen oxidation. If high concentration of Co catalyst is applied, the yield can be further enhanced 4-5 percentage. It is focused on the discussion of process parameter such as temperature, reaction period, and substrate concentration in autoxidation of o-nitrotoluene in alkali system, and the yield of o-nitrobenzalhyde is 30% under optimum condition. It is also showed that the strong base has some co-catalysis effect on reaction and the yield is also remarkably affected by solvent. The small molecule amine with ether bond is the best solvent for preparation. The consecutive reaction kinetics model is set up and the rate k, k, is also calculated out. The reaction mechanism is studied via KPR. and it is substantially concluded that the reaction first undergoes the abstract of hydrogen and then complies radical mechanism.