HERSTELLUNG VON SUBSTITUIERTEN BENZOTRICHLORIDEN

A process for chlorinating a compound of the formula (I) in which R1 is a C1-alkyl radical, C1-alkoxy radical or C1-thioalkyl radical, and X1, X2, X3 and X4 are identical or different hydrogen or halogen, and X3 may alternatively be or -NCO, comprising, in an initial phase, dissolving a chlorination catalyst in the compound to be chlorinated, continuously metering this solution together with chlorine into a reaction vessel containing the compound to be chlorinated, and, after the initial phase, removing partially or fully chlorinated compounds from the reaction vessel, dissolving fresh chlorination catalyst in the removed compounds, and feeding this catalyst solution, together with chlorine, to the reaction vessel.