SYNTHESES OF TRIFLUOROMETHYLATED PYRIDINONES AND PYRIMIDINONES

Although a large number of 6-(trifluoromethyl)uracils1-5 and 6-(trifluoromethyl)-4(3H)-pyrimidinones6,7 are known, there are few reported 2-(trifluoromethyl)-4(1H)-pyridinones8-10 prior to our own investigation of the cyclization of alkyl 2-acetyl-3-amino-4,4,4-trifluorocrotonates to 2-(trifluororaethyl)-3-carboalkoxy-4(l/f)-pyridinones,11 and the l-alkyl-4-(trifluoromethyl)-6(l/f)-pyrimidinones are unknown. Most of the reported 6-(trifluoromethyl)-uracils are derived from ethyl 4,4,4-trifluoroacetoacetate,3, 4ethyl 3-amino-4,4,4-trifluorocrotonate,2 or 3,4,4,4-tetra-fluorocrotonamides.6 The 6-(trifluoromethyl)-4(3tf)-py-rimidinones generally are prepared from reaction of am-idines with ethyl 4,4,4-trifluoroacetoacetate.6” The re-ported 2-(trifluoromethyl)-4(li)-pyridinones are derivedfrom cyclization of 1,1,1,7,7,7-hexafluoroheptane-2,4,6-trione,8 hydrolysis of 4-halo-2-(trifluoromethyl)pyridines,9 or reaction of 2-(trifluoromethyl)-6H-l,3-oxazin-6-ones, the products from the reaction of 3-aminoacrylates with tri-fluoroacetic anhydride, with Reformatsky reagent.10 We are interested in the synthesis of l-methyl-2-(trifluoro-methyl)-4(l/f)-pyridinone (1) due to its structural resem- blance to a commercial herbicide, fluridone (2).12 Recently we reported a one-step synthesis of a 6-(trifluoro-methyDuracil from reaction of AT-(cyanoacetyl)urethane with trifluoroacetonitrile.1 We would like to communicate here the convenient syntheses of 2-(trifluoromethyl)-4- lH)-pyridinones and a 4-(trifluoromethyl)-6(lH)-pyri-midinone with trifluoroacetonitrile as the starting material. © 1990, American Chemical Society. All rights reserved.