Expired Canadian patentCanada
Halogenated alkyl theophyllines and methods for their preparation and use
CA 632047 A · Owner: Sheppard, Harry A. · Inventors: Sheppard, Harry A.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordRead 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 December 5, 1961. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 5, 1978.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 23, 1954
GrantedDecember 5, 1961
Term endedDecember 5, 1978
Patent numberCA 632047 A
Classification (IPC)C07D
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.