Abstract: Process for the preparation of polyhalogenated benzotrifluorides, benzotrichlorides and benzoyl chlorides and new trihalogeno-benzotrichlorides and -benzoyl chloridesPolyhalogenated benzotrifluorides can be reacted with chlorides from the series of Friedel-Crafts catalysts to give the corresponding benzotrichlorides, which can be hydrolysed by water in the presence of iron(III) chloride to give the corresponding benzoyl chlorides. These are suitable as intermediate products for the preparation of active compounds for medicaments and feed additives.

Abstract: A process for preparing chlorodifluoroacetyl chloride from 1,1-difluoro-2,2-dichloroethylene and dichloroacetyl chloride from trichloroethylene or 1,1,2,2-tetrachloroethane, in which the starting compounds are continuously reacted in the gaseous phase with oxygen to obtain a photochemical oxidation reaction, chlorine being added as a sensitizer, the reaction mixture being irradiated with light having a wavelength .lambda..gtoreq.280 nm, the reaction preferably being carried out unpressurized. Particularly high yields with height selectivity are achieved by using doped high pressure mercury vapor lamps to irradiate the reaction mixture.

Abstract: A process is disclosed for preparing polyhaloacyl fluorides such as trifluoroacetyl fluoride and difluoroacetyl fluoride by oxidizing 1-chloro-1,2,2,2-trifluoroethanes and 1,1-dichloro-2,2-difluoroethane, respectively with oxygen.

Abstract: The invention relates to a process for the preparation of dichloroacetyl chloride by oxidation of trichloroethylene under pressure and at elevated temperature in the presence of a certain secondary aliphatic or cycloaliphatic amine of the formula HNR.sup.1 R.sup.2 in which R.sup.1 and R.sup.2 are identical or different and are an alkyl radical having 1 to 10 carbon atoms, where at least one of the radicals R.sup.1 and R.sup.2 has a tertiary structure, or R.sup.1 and R.sup.2 together with the nitrogen atom form a 5- to 10-membered ring, where at least one of the carbon atoms adjacent to the nitrogen is a tertiary carbon atom. Good yields of the acid chloride and low trichloroethylene oxide contents are obtained in one process step.

Abstract: Process for the preparation of .alpha.-fluoroacrylic acid derivatives from 2,2-difluoro-1-methyl-cyclopropyl compounds and new 1,1-difluoro-2-halogenoethyl (halogeno)methyl ketones obtainable in this process as intermediates.

Abstract: In the conversion of trichloroethene and tetrachloroethene into dichloroacetyl chloride (DAC) or trichloroacetyl chloride (TAC) by means of oxygen, the reaction mixture is passed several times as a thin film through the reaction zone. The reaction time for achieving a certain conversion is in this way reduced.In the preparation of DAC, a constant content of acid chloride is established in the reaction mixture by removing some of the mixture and working this up by distillation, while the circulating reaction mixture is simultaneously topped up with fresh trichloroethene.In this way, side reactions are suppressed and the amount of by-products is reduced.