| abstract |
The invention relates to a method for producing chlorocarboxylic acid chlorides of formula (I), wherein R<1> and R<2>, independently from one another, mean a hydrogen atom, an organic radical containing carbon, a halogen, a nitro or cyano group and Y means an alkylene chain having 1 to 10 carbon atoms in the chain which is unsubstituted or is substituted by organic radicals that contain carbon, by halogen, nitro and/or cyano groups, whereby the alkylene chain can be interrupted by an ether-, thioether-, tertiary amino- or keto group, whereby the organic radicals of Y and/or R<1> and/or R<2> can be connected to one another and thereby form a non-aromatic system, whereby said radicals contain carbon, by converting a lactone of formula (II), wherein R<1>, R<2> and Y have the aforementioned meanings, using a hydrogen chloride and phosgene in the presence of a catalyst. Hydrogen chloride is added before and/or while phosgene is added. The hydrogen chloride is only introduced at a temperature of at least 60 DEG C. A pyridine compound is used as the catalyst. |