1-azaxanthone-3-carboxylic acids
CA 1087188 A · Owner: Takeda Chemical Industries, Ltd. · Inventors: Ukawa, Kiyoshi; Nohara, Akira; Sugihara, Hirosada
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 novel 1azaxanthone-3-carboxylic acid and its derivatives usable for effective medicines for the treatment of allergic diseases, which are shown by the following formula (I), (I), wherein R1 is hydrogen alkyl, phenyl, carboxyl, hydroxyl, alkoxy or amino group which may be unsubstituted or substituted by one alkyl m is, 0, 1 or 2 and R2 is alkyl, alkoxy halogen, nitro, hydroxy, carboxyl, butadienylene (-CH=CH-CH=CH-) which forms a benzene ring with any adjacent carbon atoms or amino group which may be unsubstituted or substituted by at least one alkyl, and their physiologically acceptable salts.
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
- Granted October 7, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 7, 1997.
- 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.