Process for the preparation of racemic citalopram and/or S-or R-citalopram by separation of a mixture of R-and S-citalopram
US7112686B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2002 |
| Grant date | Sep 26, 2006 |
| Priority date | — |
| Expiry date | Jun 25, 2022 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61P25/24
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of racemic citalopram free base or an acid addition salt thereof and/or R- or S-citalopram as the free base or an acid addition salt thereof by separation of a mixture of R- and S-citalopram with more than 50% of one of the enantiomers into a fraction consisting of racemic citalopram and/or a fraction of S-citalopram or R-citalopram characterized in that i) citalopram is precipitated from a solvent as the free base or as an acid addition salt thereof; ii) the precipitate formed is separated from the mother liquor; iia) if the precipitate is crystalline it is optionally recrystallised one or more times to form racemic citalopram, and then optionally converted into an acid addition salt thereof; iib) if the precipitate is not crystalline, steps i) and ii) are optionally repeated until a crystalline precipitate is obtained and the crystalline precipitate is recrystallised one or more times to form racemic citalopram, and then optionally converted into an acid addition salt thereof; iii) the mother liquor is optionally subjected to further purification and S-citalopram or R-citalopram is isolated from the mother liquor and optional…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.