Process for the preparation of phenyl carbonates
CA 2094709 A1 · Owner: Tuinstra, Hendrik E. · Inventors: Tuinstra, Hendrik E.; Rand, Cynthia L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the preparation of an aromatic carbonate from a phenol, acetic anhydride, carbon monoxide and oxygen comprising the steps of A) reacting acetic anhydride with phenol to form phenyl acetate; B) reacting the phenyl acetate with dimethyl carbonate to produce a phenyl carbonate and methyl acetate; and C) reacting the methyl acetate with carbone monoxide to produce acetic anhydride for use in step A.
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 November 21, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 21, 2012.
- 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.