The first synthesis of 8-aza-2-polyfluoroalkylchromones
摘要:
The condensation of 3-acetyl-4,6-dimethyl-2-pyridone with RFCO2Et in the presence of LiH in dioxane affords corresponding R-F-containing beta-diketones, whose dehydration under the action of conc. H2SO4 gives 8-aza-5,7-dimethyl-2-polyfluoroalkylchromones. (C) 2002 Elsevier Science B.V. All rights reserved.
Unexpected dimerization of 5,7-dimethyl-2-trifluoromethyl-8-azachromone induced by hydrogen sulfide
作者:M. A. Barabanov、V. Ya. Sosnovskikh、V. S. Moshkin、M. I. Kodess
DOI:10.1007/s11172-010-0360-4
日期:2010.11
Depending on the reaction conditions, the reaction of 5,7-dimethyl-2-trifluoromethyl-8-azachromone with hydrogen sulfide afforded cyclic and linear dimers with the S-S bond. The regio- and stereochemistry of the reaction products were determined by 1H and 13C NMR spectroscopy.
Nucleophilic trifluoromethylation of RF-containing 4-quinolones, 8-aza- and 1-thiochromones with (trifluoromethyl)trimethylsilane
作者:Vyacheslav Ya. Sosnovskikh、Boris I. Usachev、Dmitri V. Sevenard、Gerd-Volker Röschenthaler
DOI:10.1016/j.jfluchem.2005.03.001
日期:2005.5
Reactions of N-substituted 2-polyfluoroalkyl-4-quinolones and 8-aza-5,7-dimethyl-2-polyfluoroalkylchromones with (trifluoromethyl)-trimethylsilane proceed mainly as a 1,4-nucleophilic trifluoromethylation to give N-substituted 2,2-bis(polyfluoroalkyl)-2,3-dihydroquinolin-4(1H)-ones and 5,7-dimethyl-2,2-bis(polyfluoroalkyl)-2,3-dihydro-4H-pyrano[2,3-b]pyridin-4-ones after acid hydrolysis. Similar reaction with 2-trifluoromethyl-4H-thiochromen-4-one proceeds as a 1,2-addition to give 2,4-bis(trifluoromethyl)-4H-thiochromen-4-yl trimethylsilyl ether. (c) 2005 Elsevier B.V. All rights reserved.