摘要
提出采用间接电合成法以Ce4+/Ce3+为媒质,在高剪切混合乳化机搅拌下使Ce4+氧化对溴甲苯合成对溴苯甲醛工艺,使用后的媒质再生循环使用,无三废排放。在隔膜电解槽中Ce3+电氧化的最佳条件是c(Ce3+)=0 8mol/L;c(H2SO4)=0 3mol/L;电流密度200A/m2;电量1 0F/mol,Ce4+的电解收率90 9%。槽外合成对溴苯甲醛的最佳条件是n(Ce4+)∶n(p Br—C6H4—CH3)=4∶1;c(H2SO4)=0 3mol/L;反应温度85℃,对溴苯甲醛反应收率78 5%,Ag+催化下对溴苯甲醛反应收率90 3%。
Ce3+ in sulphuric acid solution is electrooxidized to Ce4+ in a membrane electrolytic cell.Then the Ce4+ solution is mixed with pbromotoluene to produce pbromobenzaldehyde in an emulsifying stirrer.The purified mother liquid returns to the cell to be used cyclically without pollution.The optimum conditions of electrolysis are Ce3+ 08 mol/L,sulfuric acid 03 mol/L,current density 200 A/m2 and electric quantity 10 F/mol.Under these conditions the electrolytic yield is 909%.The optimum conditions of outside cell reaction are n(Ce4+)∶n(pBr-C6H4-CH3)=4∶1,sulfuric acid 03 mol/L and reaction temperature 85 ℃.Yield of pbromobenzaldehyde is 785%.With Ag+ catalyzer,the yield of pbromobenzaldehyde reaches 903%.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2003年第3期169-171,181,共4页
Fine Chemicals
关键词
间接电氧化合成
对溴苯甲醛
对溴甲苯
p-bromobenzaldehye
p-bromotoluene
indirect electrosynthesis
