Abstract: The invention relates to 2-alkylmercapto-4-(trifluoromethyl)benzoic esters of the formula (II), in which R.sup.1 and R.sup.2 are, independently of each other, (C.sub.1 -C.sub.6) alkyl, and a process for their preparation, which comprises reacting 3,4-dichlorobenzotrifluoride electrochemically at an anode with CO.sub.2 to give 2-chloro-4-(trifluoromethyl)-benzoate, converting it into the corresponding benzoic ester of the formula (I), and then reacting it with an alkylmercaptide R.sup.2 S.sup.e.

Abstract: In the preparation processes known hitherto for haloacrylic acids and deuterated derivatives thereof, it is necessary to use chemicals, some of which are very toxic or very expensive.However, fluoroacrylic acids are successively prepared from halogenated fluoropropionic acids and derivatives thereof by electrochemical elimination of halogen atoms.For this purpose, the acids or derivatives thereof are electrolyzed in a water-containing solution at a temperature from -10.degree. C. to the boiling point of the electrolysis liquid.

Abstract: The invention relates to a process for preparing compounds of the formula(I) R.sub.1 --O--CF.dbd.CF.sub.2by elimination of halogen atoms from compounds of the formula ##STR1## by electrolysis. The compounds of the formula (II) are electrolyzed in an undivided or divided electrolysis cell in an organic liquid which can also contain water at a temperature from -20.degree. C. to the boiling temperature of the electrolyte or catholyte at a current density of 1-500 mA/cm.sup.2 at a cathode made of lead, cadmium, zinc, copper, tin, zirconium, mercury, alloys of these metals or carbon.

Abstract: The existing processes for the preparation of halogenoacrylic acids and deuterated derivatives thereof have to be carried out using chemicals which are in some cases very toxic or very expensive.Electrochemical reduction, however, makes it possible to eliminate one or more halogen atoms selectively from halogenoacrylic and halogenomethacrylic acids and derivatives thereof, and to replace these by hydrogen or deuterium atoms.This is effected by electrolyzing the acids or derivatives thereof in a solution containing water or deuterium oxide at a temperature from -10.degree. C. up to the boiling point of the electrolysis liquid.