Synthesis of N-polyfluorinated alkyl derivatives of uracil and 5-substituted uracils X-ray structure of a mono N-substituted 5-trifluoromethyluracil

The treatment of uracil (A), 5-trifluoromethyluracil (B), 5-chlorouracil (C ), 5-fluorouracil (D), and 5-nitrouracil (E) with 1-iodo-1H, 1H,2H,2H-perfl uorooctane (F) in the presence of sodium carbonate gave the corresponding 1 ,3-di(1H,1H, 2H,2H-perfluorooctyl)uracil (1), 1,3-di(1H,1H,2H,2H-perfluoroo ctyl)-5-trifluoromethyluracil (3), 1,3-di(1H,1H,2H,2H-perfluorooctyl)-5-chl orouracil (5), 1,3-di(1H,1H,2H,2H-perfluorooctyl)-5-fluorouracil (7) and 1, 3-di(1H,1H,2H,2H-perfluorooctyl)-5-nitrouracil (9) in reasonably good yield s. In analogous reactions, 4-iodo-2-(trifluoromethyl)-1,1,1,2-tetrafluorobu tane (G) reacted smoothly with A-E to form the respective 1,3-disubstituted derivatives 2, 4, 6, 8 and 10 in moderate yields. The structure of the onl y mono-substituted product isolated from this series of reactions, in this case between B and F to give 1-mono(1H,1H,2H,2H-perfluorooctyl)-5-trifluoro methyluracil (11), was determined from X-ray diffraction studies. The compo unds were characterized by using IR, and H-1 and F-19 NMR spectroscopy, and MS and HRMS. (C) 2000 Elsevier Science S.A. All rights reserved.