title: Efficient Lewis acid ionic liquid-catalyzed synthesis of the key intermediate of coenzyme Q10 under microwave irradiation.
abstract: An efficient synthesis of a valuable intermediate of coenzyme Q(10) by microwave-assisted Lewis acidic ionic liquid (IL)-catalyzed Friedel-Crafts alkylation is reported. The acidity of six [Etpy]BF(4)-based ionic liquids was characterized by means of the FT-IR technique using acetonitrile as a molecular probe. The catalytic activities of these ionic liquids were correlated with their Lewis acidity. With increasing Lewis acid strength of the ionic liquids, their catalytic activity in the Friedel-Crafts reaction increased, except for [Etpy]BF(4)-AlCl(3). The effects of the reaction system, the molar fraction of Lewis acid in the Lewis acid ILs and heating techniques were also investigated. Among the six Lewis acid ionic liquids tested [Etpy]BF(4)-ZnCl(2) showed the best catalytic activity, with a yield of 89% after a very short reaction time (150 seconds). This procedure has the advantages of higher efficiency, better reusability of ILs, energy conservation and eco-friendliness. The method has practical value for preparation of CoQ(10) on an industrial scale.
authors.affiliation: Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.forename: Yuangang
authors.initials: Y
authors.lastname: Zu
authors.forename: Yujie
authors.initials: Y
authors.lastname: Fu
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Yu
authors.forename: Guoyong
authors.initials: G
authors.lastname: Sun
authors.forename: Thomas
authors.initials: T
authors.lastname: Efferth
mesh_terms: D052578:Ionic Liquids / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D008872:Microwaves; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D052578:Ionic Liquids; D058116:Lewis Acids; D014451:Ubiquinone; C024989:coenzyme Q10