Trifluoromethyl compounds of the formulas ##EQU1## are useful as oil repellants. Substituted barbituric acid derivatives thereof of the formula ##EQU2## are useful as central nervous system depressants for animals. Trifluoromethylfluorocarbonylketene and trifluoromethylmalonyl fluoride are prepared by reacting perfluoromethylacryloyl fluoride with a carboxylic acid.