Electrochemical Regeneration Of Tetrachloro-P-Benzoquinone (P-Chloranil) And Its Application

Quinones(DDQ and tetrachlorobenzoquinone)are widely used in medicinal chemistry and synthetic chemistry because they can be used as dehydrogenation oxidant for compounds.On the other hand,thiazole,as an important class of five-membered aromatic heterocyclic compounds,plays a very important role in many fields.At present,thiazole is usually used in the industry to oxidize dehydrogenation of dihydrothiazole to produce thiazole,but the reaction conditions are harsh,the pollution is serious,and the product yield is low.Therefore,it is a very meaningful work to establish a green and highly efficient method for the regeneration of TCQ and its application to the synthesis of thiazole.In this paper,the oxidative regeneration of TCQ was studied.The electrochemical regeneration was studied.The cyclic voltammetry(CV)method was used to systematically study the catalytic oxidation effect of TCHQ with different halogen ions as electrocatalyst.The reaction conditions were used to electrochemically regenerate TCQ and applied to the electrochemical synthesis of thiazole to establish a green synthesis process of thiazole compound.This paper mainly carried out the following two aspects of research:1.Study on regeneration method of TCQ1)A method for regenerating TCQ by hydrogen peroxide oxidation has been established.Firstly,the reaction conditions were optimized,and then the expanded reaction was carried out under the optimal reaction conditions.The reaction was proved to have a good application prospect by recycling the reaction solvent.The reaction is carried out in a conventional simple reaction apparatus,using methanol as a solvent,hydrogen peroxide as an oxidant,concentrated sulfuric acid as an additive,and finally,the product can be separated by simple filtration,and the solvent can be recycled and recycled.Therefore,it is a method for regenerating TCQ which is easy to operate,green and environmentally friendly,and has broad application prospects.2)A method for electrochemically regenerating TCQ with halogen ions as an electrocatalyst was established.First,the cyclic voltammetry method was used to test the CV curve of different halogen ions as electrocatalysts,and the bromide ion was determined to be the optimal electrocatalyst.Next,the effects of a series of reaction factors on the actual electrical response were investigated,and the optimal reaction conditions were obtained.Under this condition,an expanded amount of reaction was carried out,which proved the industrial application prospect of the regeneration method.The reaction can be carried out in a simple single-chamber electrolyzer,with sodium bromide as an electrocatalyst,methanol as a solvent,cheap and easily available graphite as a working electrode,and regeneration of TCQ by "clean energy" electrons.Therefore,it is a method for electrochemically regenerating TCQ with low cost,easy operation,environmental friendliness and broad application prospect,and provides a new idea for the regeneration of quinones.2.Electrochemical Synthesis of Thiazole CompoundsBased on the electrochemical regeneration of TCQ,the electrochemical synthesis of thiazole was studied.A method for electrochemical synthesis of thiazole was established.Firstly,the cyclic voltammetry method was used to test the CV curve of the TCHQ monocatalytic system and the bromide/TCHQ dual catalytic system,and the optimal double catalytic system was determined.Next,the actual reaction conditions were optimized,and the optimal reaction conditions were obtained.Under these conditions,the reactivity of different substrates was studied.Finally,the possible reaction mechanism was inferred by cyclic voltammetry test results and related literature reports.The reaction is carried out in a simple single-chamber electrolyzer with constant current electrolysis.The reaction does not require the addition of additional supporting electrolytes and additives,and the synthesis of the thiazole compound is achieved by electrochemical method,thus being a green and easy-to-control thiazole synthesis process.Has a certain research and application value.