Process for the preparation of chloropyridine sulphonic acid chlorides
AssigneeRuetgers Organics GmbH
InventorsBruno Biedenbach, Hans-Peter Michel
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Abstract
A process is disclosed for preparing chlorinated pyridinesulphonic acid chlorides of the general formula I from hydroxypyridine-sulphonic acids of the general formula II The process generally entails a) passing chlorine gas into a mixture of a hydroxypyridine-sulphonic acid and of phosphorus trichloride; b) heating the mixture of a) to temperatures of about 100 to about 120° C.; c) removing any phosphorus oxychloride formed and any excess phosphorus trichloride by distillation; d) taking up the residue with an organic solvent; and e) distilling the liquid phase in a vacuum, thereby obtaining the chlorinated pyridine-sulphonic acid chloride.
Claims7
A process for preparing chlorinated pyridinesulphonic acid chlorides of the general formula I
- from hydroxypyridine-sulphonic acids of the general formula II
- comprising
- a) passing chlorine gas into a mixture of a hydroxypyridine-sulphonic acid and of phosphorus trichloride;
- b) heating the mixture of a) to temperatures of about 100 to about 120° C.;
- c) removing any phosphorus oxychloride formed and any excess phosphorus trichloride by distillation;
- d) taking up the residue with an organic solvent;
- and
- e) distilling the liquid phase in a vacuum, thereby obtaining the chlorinated pyridine-sulphonic acid chloride.
Dependencies are inferred from the claim text.