Solventless synthesis of hydrophilic phenol ester derivatives
CA 2424717 A1 · Owner: Gibson, Michael Steven · Inventors: Majerczak, Victoria Ann; Orlando, Robert James; Gibson, Michael Steven
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for preparing benzenesulfonate salts from an appropriately substituted acid chloride and a hydroxybenzenesulfonic acid is conducted in the absence of solvent, in a molar excess of acid chloride and in the presence of a phase transfer catalyst selected from quaternary ammonium and quaternary phosphonium salts and the target reaction product. The molar excess of the acid chloride is used to reduce the occurrence of gelation in the product.
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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 November 14, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 14, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 14, 2023.
- 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.