Method for the preparation of citalopram
US6291689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 2000 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | May 3, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D307/87
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method for the preparation of citalopram is described comprising reduction of the oxo group of a compound of formula (IV), ##STR1## wherein R.sup.1 is CN, C.sub.1-6 alkyloxycarbonyl or C.sub.1-6 alkylaminocarbonyl, ring closure of the resulting hydroxy compound thereby obtaining the corresponding 1-(4-fluorophenyl)-1,3-dihydroisobenzofuran, then if R.sup.1 is cyano using it directly in the next step and if R.sup.1 is C.sub.1-6 alkyloxycarbonyl or C.sub.1-6 alkylaminocarbonyl, conversion of the compound to the corresponding compound wherein R.sup.1 is a cyano; and alkylation of the resulting 5-cyano compound with 3-dimethyl-aminopropylhalogenide in basic conditions thereby obtaining citalopram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.