7-amino-2-heptenoates and their use in the preparation of methylphenidate
CA 2243544 C · Owner: Fox, Martin Edward · Inventors: Fox, Martin Edward; Paul, Jane Marie
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel compounds are of the formula Y1Y2N-(CH2)4-CH=C(Ph)-X wherein Y1 and Y2 are independently H or a removable blocking group or Y1 and Y2 together are a , removable divalent blocking group; and X is COOCH3 or a group convertible thereto. Such a compound may be cyclised by Michael addition, to give , methylphenidate if necessary after removing blocking group(s) and converting X to COOCH3.
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 21, 1997 and granted November 19, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 21, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 21, 2019.
- 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.