Process for the preparation of castanospermine
CA 2037608 C · Owner: Merrell Dow Pharmaceuticals Inc. · Inventors: Creemer, Laura J.; Angell, Paul T.; Anzeveno, Peter B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Castanospermine is prepared by starting from 5-(t-BOC)amino-5-deoxy-1,2-O-isopropylidene-.alpha.-D-glucuronolactone. Two additional carbons are added to the starting material using ethyl acetate and a strong base and the resulting cyclic hemiketal is subjected to a series of reductions with intervening removal of protecting groups to give the, castanospermine. A substituted hydroxypyrrolidinone and a substituted hydroxypyrrolidine serve as intermediates in the process.
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 March 6, 1991 and granted November 21, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 6, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 6, 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.