Acid fluorides and 1,1-difluoroethyl methyl ethers as new organic sources of fluoride for antimony pentachloride-catalyzed halogen-exchange reactions
作者:Keith Ramig、Linas V Kudzma、Ralph A Lessor、Leonid A Rozov
DOI:10.1016/s0022-1139(98)00347-9
日期:1999.2
1-Difluoroethyl methyl ethers such as the commercial veterinary anesthetic methoxyflurane (2,2-dichoro-1,1-difluoroethyl methyl ether, 6) decompose in the presence of a catalytic amount of antimony pentachloride. The rate of decomposition is dependent upon the number and position of halogen atoms in the ether: a high degree of halogenation at the methyl group or at the 2-position of the ethyl group makes
1,1-二氟乙基甲基醚,例如市售的兽用麻醉药甲氧基氟烷(2,2-二氯-1,1-二氟乙基甲基醚,6)在催化量的五氯化锑的存在下分解。分解速率取决于醚中卤素原子的数目和位置:在甲基或乙基的2位上的高度卤化程度使醚不易分解。分解产物是酰基氟和卤代甲烷。五氯化锑的命运被转化为氟氯锑物种,可以原位使用该氟氯锑物种以选择性地氟化多氯化基质。因此,1,2,2,2-四氯-1-氟乙基甲基醚(1利用6作为氟化物源,利用2和6对五价锑物种的稳定性差异,将)干净地转化为麻醉剂化合物2,2,2-三氯-1,1-二氟乙基甲基醚(2)。还证明了由1,1-二氟乙基甲基醚分解得到的酸性氟化物是卤代反应的氟化物来源。