Colchicine derivatives
CA 2521990 C · Owner: Yang, Li-Xi · Inventors: Yang, Li-Xi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Certain N-deacetylcolchicine and N-deacetylthiocolchine derivatives are described wherein the , 7-N position on the B ring is substituted with the group - C(0)-(CHR4)m-AR wherein m is an , integer of 0-10, A is S O, N or a covalent bond; R1 is substituted phenyl or substituted benzoyl; , optionally substituted cycloalkyl of 3-7 carbons; optionally substituted naphtyl; an optionally , substituted imide ring; an optionally substituted 5 or 6 member heterocycle with at least one N, S, or O in the ring; or an optionally substituted fused heterocyclic or fused carboxyclic ring , system; R2 (at the 2-position of the A ring) is methoxy hydroxy, or , methylenedioxy when taken together with R3; …
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 April 14, 2004 and granted March 17, 2015. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 14, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 14, 2026.
- 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.