The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 28, 2013
Filed:
Dec. 28, 2005
Leszek Dembkowski, Pruszcz Gdański, PL;
Robert Rynkiewicz, Starogard Gdański, PL;
Janusz Rachoń, Gdańsk, PL;
Slawomir Makowiec, Gdańsk, PL;
Witold Przychodzeń, Gdańsk, PL;
Dariusz Witt, Gdańsk, PL;
Leszek Dembkowski, Pruszcz Gdański, PL;
Robert Rynkiewicz, Starogard Gdański, PL;
Janusz Rachoń, Gdańsk, PL;
Slawomir Makowiec, Gdańsk, PL;
Witold Przychodzeń, Gdańsk, PL;
Dariusz Witt, Gdańsk, PL;
Zaklady Farmaceutyczne Polpharma S.A., Gdansk, PL;
Abstract
The invention relates to a novel process for the preparation of [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid and hemipentahydrate monosodium salt thereof comprising (a) reacting an aqueous solution of 3-pyridyl acetic acid hydrochloride with phosphorus trichloride; (b) removing unreacted phosphorus trichloride; (c) adding water and hydrolyzing; (d) isolating crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid; (e) suspending said crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid in water; (f) adding sodium hydroxide, filtering off, and washing; and (g) drying obtained hemipentahydrate monosodium salt of 1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid.