The present invention provides a process to prepare a halogenated carbonyl group-containing compound by electrochemically reacting the corresponding carbonyl group-containing compound with a hydrogen halide H—X, an organic halide R′—X and/or a halide salt Mn+—Xn− under substantially water-free conditions, wherein X is a chlorine, bromine or iodine atom, R′ is an alkyl or aryl group that may be linear or branched, optionally containing one or more heteroatoms such as oxygen, nitrogen, chloride, bromide, fluoride or iodide of which the halogen atom X can be electrochemically split off, Mn+ is a quaternary ammonium, alkaline earth metal, alkali metal or metal cation, and n is an integer of 1 to 5, depending on the valency of the metal cation Mn+.