Heterocyclic compounds
CA 2043071 C · Owner: Miwa, Yoshikazu · Inventors: Miwa, Yoshikazu; Ichikawa, Shunji; Ishii, Akio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed a heterocyclic compound represented by general formula:, (See Fig. I) wherein R1 represents hydrogen, lower alkyl or aryl; R2 represents hydrogen, hydroxyl or lower alkyl; A represents CH or N; X represents -O- or -NH-; R3 represents hydrogen hydroxyl or lower alkyl; R4 represents lower alkyl; and n represents 0 or 1, or a pharmaceutically acceptable salt thereof. The compound and pharmaceutically acceptable salt are useful as antiemetics and suppressant of migraine.
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 May 23, 1991 and granted February 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 23, 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.