Process for the preparation of ethers of clavulanic acid
CA 1097654 A · Owner: Beecham Group Limited · Inventors: Ponsford, Roger J.; Howarth, Thomas T.; Luk, Kong
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed for the preparation of a compound of the formula (II):, (II), wherein R1 is a group such that CO2R1 is an ester group, R3 is a hydrogen atom or an alkyl group of 1-4 carbon atoms, R4 is a hydrogen atom or an alkyl group of 1-4 carbon atoms and R5 is a group such that the CR3R4R5 moiety is an inert organic group of up to 18 carbon atoms; which process comprises the reaction of a compound of the formula (III): (III), wherein R1 is as defined in relation to formula (II) with a compound of the formula (IV);, (IV) wherein X is I, Br, or Cl and R3, R4 and R5 are defined in relation to formula (II); in the presence of a source of silver ions.
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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 March 17, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 17, 1998.
- 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.