Synthesis And Process Optimizationof Several Phenolic Intermediates

In recent years,the phenol products were widely used in many fields as energy industry and fine chemical industry developed rapidly in China.p-cresol is an important organic chemical intermediates mainly used for the synthesis of antioxidants,pharmaceuticals,perfumes,dyes,pesticides,light stabilizers and so on.o-cresol is the basic raw material for the production of herbicides,insecticides,tanning agents and Lysol disinfectant.These two cresol have potential application,but both quantity and quality can't satisfy domestic need according to small scale,backward technology and poor product quality of most temporary cresol manufacturers,resulted in limited research and application of its downstream products.2,5-dichlorophenol is an important raw material to synthesize 3,6-dichloro salicylic acid benzoin series herbicide dicamba.It has a very wide range and broad prospects in agriculture.This thesis mainly includes following several aspects,1.Hydrolysis of p-bromotoluene.The principle of hydrolysis was discussed,and then the optimum conditions was determined by controlling variable factors,respectively.The reaction of the sodium salt was acidified,extracted and tested by HPLC.2.Hydrolysis of o-bromotoluene.The principle of hydrolysis was discussed,and then the optimum conditions was determined by controlling variable factors,respectively.The reaction of the sodium salt was acidified,extracted and tested by HPLC.3.Hydrolysis and amplification test of mix bromotoluenes.The principle of hydrolysis was discussed,and then the optimum conditions was determined by controlling variable factors,respectively.The reaction of the sodium salt was acidified,extracted and tested by HPLC.4.Synthesis of 2,5-dichlorophenol.The phenol sodium salt was prepared by hydrolysis of trichlorobenzene,then 2,5-dichloro-phenol was obtained through acidified and urea eutectic purification and tested by HPLC.The optimum reaction conditions such as the reaction temperature,the amount of catalyst,the molar ratio of raw materials,etc.Were obtained by the above experimental results.Compared with the traditional method,it has the advantages of high purity,high yield,by-product and less product stability.As compared with toluene chlorination hydrolysis.The reaction temperature of 200 ? is lower than that of the hydrolysis of toluene at 425 ?.The reaction temperature of toluene hydrolysis is too high,which leads to more byproducts and the isomerization of chlorotoluene.Isopropyltoluene process long alkylated methyl cumene oxidation may be oxidized methyl will eventually produce propofol and formaldehyde,propofol,cresol,formaldehyde will react to produce phenolic resin.Toluene sulfonation production of alkali melting equipment corrosion and environmental pollution is serious,many domestic manufacturers because the environment is not standard problem was discontinued.In summary,this experiment because of all the advantages,applied to the industrial production prospects...