Study on synthesis technology of p-hydroxy acetophenone catalyzed by liquid coordination complexes
Liquid coordination complex(Ur/AlCl3)performed as both catalyst and solvent,to catalyze the Fries rearrangement reac-tion of phenyl acetate(PA)to preparep-hydroxyacetophenone(p-HAP).A series of different catalysts were compared in terms of the reaction activity,and results showed that Ur/AlCl3 exhibited higher catalytic performance under the same conditions.Compared with traditional catalysts:Ur/AlCl3 raw materials were cheaper and easy to obtain;No other components needed to be added in the process to participate the reaction,which led to low degree of side reactions in the catalytic system;With milder reaction conditions and faster reaction rate.The influence of different molar ratio,reaction time,reaction temperature and Ur/AlCl3 recycling times on the experimental results were studied,and the effects of catalyst molar ratio on its Lewis acidity and catalytic performance were veri-fied.Optimum reaction conditions were:Ur/AlCl3 molar ratio=0.6,reaction time:3 h,reaction temperature:65 ℃,n(Cat.):n(PA)=0.5:1,and the yield was 92.3％.The product structure was confirmed by 1 H-NMR,IR and MS.The catalyst still showed good catalytic activity after being recycled for four times.
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