Polyfluorinated ?-ketoesters and their ?-halogenated derivatives in reactions with tetraphosphorus decasulfide and 2,4-bis(4-(methoxyphenyl))-2,4-dithioxo-PV,PV-1,3,2,4-dithiodiphosphetane
Compounds of the formula ##STR1## are disclosed as herbicides. Disclosed herein are cyclic amides of pyridine 3,5-carboxylic acids substituted at the 2- and/or 6-position with a fluorinated methyl group. Also disclosed are herbicidal use of such compounds and compositions containing them.