Process for the production of 3-hydroxy-2-imino-(2H)-pyridinesulphonic acid monohydrate
AssigneeCiba-Geigy Corporation
InventorGunter Mattern
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Abstract
A process for the production of 3-hydroxy-2-imino-1(2H)-pyridinesulphonic acid comprising oxidation of furfurol and reaction of the oxidation product with sulphamic acid is disclosed which is carried out in the presence of an oxyacid of tri- or pentavalent phosphorus.
Claims8
Process for the production of 3-hydroxy-2-imino-1(2H)-pyridinesulphonic acid monohydrate by oxidation of furfurol and reaction of the oxidation product with sulphamic acid, which process comprises oxidising furfurol in an aqueous medium at a temperature of -10.degree. C to 0.degree. C, with a pH value of 0 to 0.5, in the presence of an oxyacid of tri- or pentavalent phosphorus or of a water-soluble salt of such an acid and with the oxidising agent being chlorine, alkali hypochlorite, bromine, sodium bromate, potassium bromate or chlorine in the presence of hydrogen bromide;
- subsequently reacting the oxidation product with 2 to 3 moles of sulphamic acid per mole of employed furfurol;
- and then separating the formed 3-hydroxy-2-imino-1(2H)-pyridinesulphonic acid monohydrate.
Dependencies are inferred from the claim text.