Preparation of riboflavin-5'-phosphate (5'-fmn) and its sodium salt, and of riboflavin-4',5'-cyclophosphoric acid ester chloride as an intermediate
CA 2000937 C · Owner: Basf Aktiengesellschaft · Inventors: Kiefer, Hans; Grimmer, Johannes
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Riboflavin-4',5'-cyclo-, phosphoric acid ester chloride of the formula I (I), its preparation by reacting an alkali metal salt of riboflavin, in an aprotic solvent, with phosphorus oxychloride, its use for the preparation of riboflavin- 5'-phosphate and of the sodium salt of riboflavin-5'phosphate, and a process for the preparation of riboflavin-5'-phosphate or its sodium salt via the novel phosphoric acid ester chloride.
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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 18, 1989 and granted March 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 18, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 18, 2011.
- 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.