Production of 1-hydroxy-alkane-1,1-diphosphonic acids
AssigneeHenkel Kommanditgesellschaft auf Aktien
InventorsHelmut Blum, Karl-Heinz Worms
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Abstract
A process for the production of 1-hydroxy-alkane-1,1-diphosphonic acids comprises reacting 1-amino-alkane-1,1-diphosphonic acids with nitrous acid, halides of nitrous acid or a substance forming nitrous acid under the reaction conditions.
Claims8
A process for the preparation of 1-hydroxy-alkane-1,1-diphosphonic acid of the formula ##STR11## wherein R is a member having from 1 to 12 carbon atoms selected from the group consisting of alkyl having 1 to 6 carbon atoms, cyclohexyl, phenyl and phenylalkyl, all having substituents selected from the group consisting of hydrogen, methyl, ethyl, methoxy, ethoxy and halogen, consisting essentially of reacting the corresponding 1-amino-alkane-1,1-diphosphonic acid of the formula ##STR12## in which R has the above-assigned meaning, with at least the stoichiometric amount of aqueous nitrous acid, at a temperature between 0.degree. and 50.degree. C;
- and recovering said 1-hydroxy-alkane-1,1-diphosphonic acid.
A process for the preparation of 1-hydroxy-ethane-1,1-diphosphonic acid of the formula ##STR13## consisting essentially of reacting the corresponding 1-amino-ethane-1,1-diphosphonic acid of the formula ##STR14## with at least the stoichiometric amount of aqueous nitrous acid, at a temperature between 0.degree. and 50.degree. C;
- and recovering said 1-hydroxy-ethane-1,1-diphosphonic acid.
Dependencies are inferred from the claim text.