Electrochemistry Synthesis Of O-Nitrobenzaldehyde

O-Nitrobenzaldehyde serves as an important medical intermediate,while there exist some defects in the conventional way of synthesizing o-nitrobenzaldehyde,such as heavy pollution,low current efficiency and complexity in the synthesizing process. The author demonstrates in this thesis that by the way of the "In-cell" indirect electrosynthesis,the above mentioned defects can be overcome. Firstly,in the conventional electrolysis device,organic compounds is likely to be absorbed by its electrode surface and the side reactions often happened,which in turn,will obstruct the electron exchange on the electode surface;Besides,the current efficiency is not ideal. In regarding to the shortcomings of the conventional device,the author intends to adopt the cycled solution electrolysis device instead in the synthesizing process so that the electrolyte is fully stirred while it is kept circulating by the mini power-pump′s drive,thus the trough voltage is lowered and remained relatively stable,and the current efficiency is greatly raised. Further,because the electrolyte is in circulatory use in put the oxidation medium V5+/V4+ and the cathode in use in the same synthesizing process.By constantly bringing in oxygen to the cathode surface,it obstructs the oxidant V5+ deoxidizing directly.More,the ?OH free radicals and H2O2 produced by the oxygen electroreduction,and V5+ work together,oxidizing the organic compounds to the target products,through which the current efficiency and selectivity in the reaction is drastically raised. In addition,because of the oxidation medium V5+/V4+keeps reproducing and is in cycle use,the oxidant consuming reduced greatly in amount. Most impprtant of all,by ways of orthogonal tests,mono-factor optimization tests and reappearance tests,the author defines the best reaction conditions for the indirectly synthesizing the o-nitrobenzaldehyde through oxidation medium V5+/V4+and the oxygen cathode electroreduction.The author also carried out tests to synthesize the aldehyde-forms of the four toluene ramifications of o-chlorotoluene,p-xylene,o-xylene and p-nitrotoluene respectively. Based on the test results,the author arrives at the conclusion that the reaction principles and device are universal and they can be employed in synthesizing indirectly many other similar organic compounds. The author establishes the way to measuring o-nitrobenzaldehyde by UV;Using IR and NMR methods to identify the products,the tests results conforms with the standard samples.