Process for the preparation of chlorinated 4,5-difluorobenzoic acids, -benzoic acid derivatives and -benzaldehydes
AssigneeHoechst Aktiengesellschaft
InventorsRalf Pfirmann, Theodor Papenfuhs, Georg Weichselbaumer
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Abstract
The present invention relates to a process for the preparation of compounds of the formula ##STR1## in which R.sup.1 is --CN, --COOH, --COOR', R' being an organic radical having 1 to 6 carbon atoms, --CONH.sub.2, --COCl or --CHO and R.sup.2 is H or Cl, which comprises reacting a compound of the formula ##STR2## in which R.sup.1 is as defined above and R.sup.3 is H or Cl, with a chlorinating agent in the presence of a chlorination catalyst at -10.degree. to 200.degree. C.
Claims15
A process for the preparation of a compound of the formula I ##STR6## in which R.sup.1 is --COOH, --COCl, --CN, or --CONH.sub.2, which comprises chlorinating a compound of the formula II ##STR7## with chlorine in a reaction medium comprising a solvent and an iodine-containing, a disulfur dichloride-containing, or iron chloride-containing chlorination catalyst, or a combination of said chlorination catalysts, in the temperature range of -10.degree. to 200.degree., wherein the R.sup.1 of formula I at the completion of said chlorinating step is identical to the R.sup.1 of formula II.
A process for the preparation of a compound of the formula I ##STR9## in which R.sup.1 is --COOH, --COCl, --CN, or --CONH.sub.2, which comprises chlorinating a compound of the formula II ##STR10## with chlorine in a reaction medium comprising a solvent and an iodine-containing, a disulfur dichloride-containing, or iron chloride-containing chlorination catalyst, or a combination of said chlorination catalysts, in the temperature range of -10.degree. to 200.degree., wherein the R.sup.1 of formula Ia at the completion of said chlorinating step is identical to the R.sup.1 of formula IIa.
Dependencies are inferred from the claim text.