Piperidine derivatives and process for their production
CA 2181089 C · Owner: D'Ambra, Thomas E. · Inventors: D'Ambra, Thomas E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to substantially pure piperidine derivative compounds as shown below wherein R1 is hydrogen or hydroxy; R2 is hydrogen; or R1 and R2 taken together form a second bond between the carbon atoms bearing R1 and R2; R3 is -COOH or -COOH4; R4 is an alkyl with 1 to 6 carbon atoms; A B, and D are the substituents of their respective rings each of which may be different or the same and are hydrogen halogens, alkyl, hydroxy, alkoxy, or other substituents. A process of preparing such piperidine derivative compounds in substantially pure form is also disclosed. (see formula I) or (see formula II)
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 June 21, 1994 and granted May 23, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 21, 2016.
- 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.