Preparation process of ginkgolide b from ginkgolide c
CA 2065501 C · Owner: Societe De Conseils De Recherches Et D'Applications Scientifiques (S.C.R .A.S.) · Inventors: Teng, Beng-Poon
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for the preparation of ginkgolide B by conversion of ginkgolide C into ginkgolide B and to the ginkgolide B thus, obtained which is a potent inhibitor of PAF-acether. The process of the present invention comprises the steps of protecting the 10-hydroxy group of ginkgolide C by conversion to an alkyl ester the reaction being effected in, dimethylformamide at a temperature of from 15 to 50°C for from 4 to 10 hours; activating the 7-hydroxy group of the resultant 10-protected ginkgolide C by conversion to a (R)thiocarbonyl ester, the activation being effected in basic conditions at a temperature of from 0 to 40°C for from 1 to 24 hours; deoxygenating the …
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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 April 7, 1992 and granted April 29, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.