Syntheses of New 4-trifluoromethylated 1,3-oxazin-6-ones From the Enamine of Ethyl Trifluoroacetoacetate

New 4-trifluoromethyl-1,3-oxazin-6-ones have been prepared in excellent yields from ethyl 3-amino-4.4.4-trifluorocrotonate (ATFC) by two original procedures: reaction of ATFC with phosgeniminium chlorides to give 2-dialkylamino-4-trifluoromethyl-1,3-oxazin-6-ones, or action of chlorinating agents on N-acyl ATFC. The reactivity of ATFC in these reactions is compared with non-fluorinated analogs.