Preparation of Fluorine-Containing Phenylacetylenes by the Method of Introduction of the Ethynyl Group Using 1,1-Dichloro-2,2-difluoroethene
作者:Kazuo Kodaira、Kunio Okuhara
DOI:10.1246/bcsj.61.1625
日期:1988.5
Phenylacetylenes (ArC≡CH) having fluoro- or trifluoromethyl substituents (o-, m-, p-F; o-, m-, p-CF3; 2,4-, 2,5-, 2,6-, 3,5-(CF3)2) have been prepared from bromobenzenes (ArBr) and benzenes (ArH) using 1,1-dichloro-2,2-difluoroethene (1) by a two-step route: ArLi or ArMgBr→ArCF=CCl2→ArC≡CLi. Upon careful treatment at −70 °C with 1, o-fluorophenyllithium gave o-FC6H4CF=CCl2 in good yield, together with benzyne-derived products, such as o-(o-FC6H4)C6H4CF=CCl2. Lithiation of m-bis(trifluoromethyl)benzene at 0 °C for 9 h (24 h) followed by treatment with bromine gave 1-bromo-2,4-, 2,6-, and 3,5-bis(trifluoromethyl)benzene in 35 (38), 31 (36), and 8% (6%) yield, respectively.
具有氟或三氟甲基取代基的苯乙炔(ArC≡CH)(邻、间、对位氟;邻、间、对位CF3;2,4-、2,5-、2,6-、3,5-双(CF3)2)已通过溴苯(ArBr)和苯(ArH)与1,1-二氯-2,2-二氟乙烯(1)的两步路线制备得到:ArLi或ArMgBr→ArCF=CCl2→ArC≡CLi。在-70°C下仔细处理时,邻氟苯基锂以良好产率生成邻FC6H4CF=CCl2,同时伴随苯炔衍生的产物,如邻(邻FC6H4)C6H4CF=CCl2。在0°C下对间双(三氟甲基)苯进行9小时(24小时)的锂化,随后用溴处理,分别以35(38)%、31(36)%和8(6)%的产率得到1-溴-2,4-、2,6-和3,5-双(三氟甲基)苯。