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Expired Canadian patentCanada

Process for the manufacture of n-(sulfonylmethyl) formamides

CA 1292479 C · Owner: Hoechst Marion Roussel · Inventors: Barendse, Nicolaas Cornelis Maria Barendse

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

N-(sulfonylmethyl)formamides are obtained by reacting a sulfinic acid, formaldehyde and formamide in the presence of a second acid and a controlled amount of water. The formamides can be converted to the corresponding sulfonylmethylisocyanides.

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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 November 26, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 26, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 15, 1987
GrantedNovember 26, 1991
Term endedNovember 26, 2008
Patent numberCA 1292479 C
Classification (IPC)C07C315/00 +2 more

Timeline

Timeline From CIPO dates

1988199119941997200020032006Application filedApril 15, 1987Patent grantedNov 26, 1991Term endedNov 26, 2008

Sources & verification

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