Preparation of codeine from morphine
CA 2502935 A1 · Owner: Mallinckrodt Inc. · Inventors: Hill, Lloyd P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for the preparation of codeine from morphine comprises the steps of: a) reacting morphine with a methylating agent in the presence of a hydrocarbon solvent at a temperature of 100 to 215 ~C under reflux conditions such that approximately 50 % or more of the hydrocarbon solvent is returned to the reaction mixture to substantially avoid the formation of codeine methyl ether; and b) recovering codeine from the reaction mixture. The process may include step a) above followed by b) cooling the reaction mixture to approximately 85 ~C and adding water to terminate the reaction; c) raising the pH of the reaction mixture to approximately 11; d) separating the hydrocarbon …
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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 October 14, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 14, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 14, 2025.
- 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.