Expired Canadian patentCanada
Process for the preparation of 5-chloro-3-chloro- sulphonyl-2-thiophenecarboxylic acid esters
CA 1333177 C · Owner: Cl Pharma Aktiengesellschaft · Inventors: Wagner, Hans Peter
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of 5-chloro-3-chlorosulphonyl-2-thiophenecarboxylic acid esters by chlorination in the presence of activated iron.
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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 22, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 22, 2011.
- 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 7, 1989
GrantedNovember 22, 1994
Term endedNovember 22, 2011
Patent numberCA 1333177 C
Classification (IPC)C07D333/38
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.