Process for the preparation of zofenopril calcium salt
US6521760B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2001 |
| Grant date | Feb 18, 2003 |
| Priority date | — |
| Expiry date | Jun 4, 2021 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61P9/12
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A process for the preparation of polymorph A of zofenopril calcium salt in substantially pure form, which comprises: a) reaction of S(−)-3-benzoylthio-2-methylpropanoic acid chloride with cis-4-phenylthio-L-proline in water at pH ranging from 9.0 to 9.5 and recovery of zofenopril in the acidic form; b) salification of acid zofenopril with a potassium salt in alcoholic solution, and recovery of the resulting potassium salt; c) conversion of the potassium salt to the calcium salt by addition of a zofenopril potassium salt aqueous solution to a CaCl2 aqueous solution at a temperature of 70-90° C. with simultaneous seeding to promote the precipitation of polymorph A.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.