Solid supported synthesis of sulfonated 2-oxopiperazines
CA 2328934 A1 · Owner: Klopfenstein, Sean Rees · Inventors: Klopfenstein, Sean Rees; Golebiowski, Adam
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The subject invention involves processes for making 2-oxopiperazine and homologous compounds using a solid support resin by (a) removing the protecting group from a N-protected amino acid ester of the resin (if present), (b) reacting the resulting unprotected resin ester with a sulfonyl chloride, (c) reacting the resulting intermediate with a N-protected amino alcohol, (d) removing the N-protecting group from the N from the amino alcohol, and (e) cleaving/cyclizing the product from the resin.
Read the whole patent
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 27, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 27, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 27, 2021.
- 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.