LUO Man, DU Jun, LIU Zuohua, et al. Synthesis of vitamin E catalyzed by [(C2H5)3NH]Cl/ZnCl2 ionic liquid[J]. CIESC Journal, 2015, (1): 126-131. DOI: 10.11949/j.issn.0438-1157.20141011.
LUO Man, DU Jun, LIU Zuohua, et al. Synthesis of vitamin E catalyzed by [(C2H5)3NH]Cl/ZnCl2 ionic liquid[J]. CIESC Journal, 2015, (1): 126-131. DOI: 10.11949/j.issn.0438-1157.20141011.DOI:
The main problems in the synthesis of vitamin E are large dosage and much loss of the catalyst
as well as difficulty to recycle the catalyst. There also exist serious environmental problems caused by contamination of water with the catalysts in the washing process. Several ionic liquids were synthesized to catalyze the synthesis of vitamin E. [(C2H5)3NH]Cl/ZnCl2 ionic liquid had the best catalytic performance. The inorganic anion in the ionic liquid played the major catalytic role
and the quaternary ammonium cation could form hydrogen bonds with isophytol easily
which enabled directed condensation reaction between isophytol and trimethylhydroquinone. The structure and acidity of [(C2H5)3NH]Cl/ZnCl2 ionic liquid were characterized by FT-IR
and its effect on production of vitamin E was investigated. With the increase of mole fraction of ZnCl2
the ionic liquid showed stronger acidity. When the mole fraction of ZnCl2 in ionic liquid was 0.66
yield of vitamin E could reach 87.4% under catalysis of [(C2H5)3NH]Cl/ZnCl2. The ionic liquid could be reused 5 times without significant decrease in catalytic performance.