Process for preparing doubly blocked 1-carba(1-dethia)-3-cephem-4-carboxylic acids
CA 2067708 A1 · Owner: Berglund, Richard A. · Inventors: Berglund, Richard A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
X-8142, Abstract, A process is provided for producing 7-protectedamino-4-protected carboxy-3-halo-1-carbacephalosporins which includes the steps of mixing the hydrochloride salt of the carbacephalosporin with a polar organic aprotic solvent having a dielectric constant of at least about 20 and a base selected from a group consisting of 5- or 6membered tertiary cyclic amine containing 0-1 oxygen atoms and dimethylbenzamine to form the free amine of a carbacephalosporin and thereafter without isolating the free amine mixing it with an acylating agent to result in the doubly blocked carbacephalosporin.
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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
- Filed April 30, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 30, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 30, 2014.
- 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.