The fluoromethyl ether sevoflurane as a fluoride source in halogen-exchange reactions
摘要:
Fluoromethyl 2,2,2-trifluoro-1-(trifluoromethyl) ethyl ether (sevoflurane), fluoromethyl 1,1,2,3,3,3-hexafluoropropyl ether, and fluoromethyl 1,2,2,2-tetrafluoroethyl ether are found to be selective fluoride donors in some halogen-exchange reactions. For example, treatment of a mixture of a polychlorinated substrate and one equivalent of sevoflurane with a catalytic amount of antimony pentachloride gives a monofluorinated product and one equivalent of chloromethyl 2,2,2-trifluoro-1-(trifluoromethyl) ethyl ether as by-product. (C) 1998 Elsevier Science S.A. All rights reserved.
The trifluoromethylgroup of certain compoundscontaining one or two trifluoromethylgroups can be converted to the carbomethoxy group by treatment with sodium methoxide followed by aqueous acidic work-up. α-Trifluoromethyl esters can be obtained by selective methanolysis of the 1,1,1,3,3,3-hexafluoroisopropyl group in some cases. The structural requirements for the transformation are delineated, and