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US 8,076,483 B2Granted
Process for the preparation of pure risedronic acid or salts
AssigneeM/s. Ind Swift Laboratories Limited
InventorsSaxena Rahul, Jain Anshul Kumar, Srinivasan Chidambaram Venkateswaran, Wadhwa Lalit
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Abstract
The present invention relates to an industrially advantageous process of making bisphosphonic acid or its salt in particular risedronic acid, [1-hydroxy-2(3-pyridinyl)ethylidene]bisphosphonic acid, having formula-(I) or its salts in high purity and high yields.
Claims4
A process for the preparation of risedronic acid of Formula I,
- Comprising the steps of:
- reacting carboxylic acid compound of Formula-II,
- with phosphorous acid and phosphorous halide in acetonitrile at a temperature of 40-80° C.;
- distilling off reaction solvent completely;
- quenching the resulting reaction mixture with water;
- refluxing the reaction mixture for sufficient time to complete hydrolysis;
- and
- isolating the pure risedronic acid of Formula I.
5 more elements
A process for the preparation of risedronic acid mono-sodium salt of Formula III,
- comprising the steps of:
- reacting carboxylic acid compound of Formula-II,
- with phosphorous acid and phosphorous halide in acetonitrile at a temperature of 40-80° C.;
- distilling off reaction solvent completely;
- quenching the resulting reaction mixture with water;
- refluxing the reaction mixture for sufficient time to complete hydrolysis;
- treating the reaction mixture with sodium hydroxide in water;
- and
- isolating risedronic acid mono-sodium salt of Formula III.
6 more elements
Dependencies are inferred from the claim text.