- Selective and efficient structural elaboration of 2-(trifluoromethyl)quinolinones
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The acid-catalyzed cyclization-condensation between anilines and ethyl 4,4,4-trifluoroacetoacetate affords 1,4-dihydro-2-trifluoromethyl-4H-4-quinolinones (1), which can easily be converted into 4-bromo-2-(trifluoromethyl)quinolines. These undergo halogen/metal exchange, generating 2-trifluoromethyl-4-quinolyllithiums, when treated with butyllithium, and hydrogen/metal exchange, generating 4-bromo-2-trifluoromethyl-3-quinolyllithiums, when treated with lithium diisopropylamide. Trapping of the latter intermediates provides 3-functionalized products that may be further elaborated by electrophilic substitution of the bromine atom. A few unexpected findings resulted from these investigations, the most noteworthy being an unprecedented buttressing effect and a counterintuitive halogen reactivity. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Marull, Marc,Schlosser, Manfred
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p. 1576 - 1588
(2007/10/03)
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