Method for synthesis of omeprazole
CA 2083605 C · Owner: Astra Aktiebolag · Inventors: Brandstrom, Arne Elof
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to an improved method for the synthesis of omeprazole, comprising the steps of reacting 5-methoxy-2-(4-methoxy-3,5-dimethyl-2-pyridinyl)methylthlo-1H-benzimidazole with m-chloroperoxy-benzoic acid in a methylene chloride solution at a substantially constant pH of about 8.0 to 8.6; extracting the reaction mixture with aqueous NaOH; separating the aqueous phase from the organic phase; and adding an alkyl formate to the aqueous phase resulting in crystallization of omeprazole. (see fig. I)
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 5, 1991 and granted December 8, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 5, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.