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Expired Canadian patentCanada

Substituted piperazine-1, 4-naphthalenediones

CA 1263650 C · Owner: American Cyanamid Company · Inventors: Torley, Lawrence W.; Tomcufcik, Andrew S.; Medwin, Jeffrey B.

CIPO record

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Abstract From the Canadian patent

61109-7500, 30,115, SUBSTITUTED PIPERAZINE-1,4-NAPHTHAALENEDIONES ABSTRACT, This disclosure describes certain substituted piperazine-1,4-naphthalenediones useful as antiasthmatic agents, having the general formula:,

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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, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 5, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 17, 1986
GrantedDecember 5, 1989
Term endedDecember 5, 2006
Patent numberCA 1263650 C
Classification (IPC)C07D295/00 +2 more

Timeline

Timeline From CIPO dates

1987198919911993199519971999200120032005Application filedDec 17, 1986Patent grantedDec 5, 1989Term endedDec 5, 2006

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.