苯甲醇液相氧化合成苯甲醛的连续流工艺

Continuous flow oxidation of benzyl alcohol to benzaldehyde

在液相条件下以苯甲醇为原料,次氯酸钠溶液为氧化剂,2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)为氧化催化剂,在连续流微通道反应器中液相氧化合成苯甲醛。考察了苯甲醇与次氯酸钠溶液的物质的量配比、催化剂用量、反应温度、溶剂以及停留时间对苯甲醛合成的影响,并进行了工艺优化。结果表明:当次氯酸钠与苯甲醇的物质的量比为1.25∶1、苯甲醇与TEMPO的物质的量比为1∶0.01、苯甲醇与DMF的体积比为1∶10、pH=8、反应温度为0℃、停留时间为10min时,苯甲醛的收率可达95.1%。

Benzaldehyde was continuously synthesized using benzyl alcohol as raw material and 2,2,6,6-tetramethyl-piperidin-1-oxyl(TEMPO)over catalyst,by the oxidation of sodium hypochlorite solution in a continuous flow micro-channel reactor under the liquid-phase conditions.The effects of reactants molar ratio,amount of catalyst,reaction temperature,solvents and residence time on the yields of product were investigated and the process conditions were optimized.The results indicate that under the conditions of n(NaClO)∶n(benzyl alcohol)=1.25∶1,n(benzyl alcohol)∶n(TEMPO)=1∶0.01,V(benzyl alcohol)∶V(DMF)=1∶10,pH=8,reaction temperature at 0℃,and residence time at 10min,the yield of benzaldehyde reaches 95.1%.