Process for producing highly pure carboxylic acid phenyl esters
CA 2069475 A1 · Owner: Nitta, Itaru · Inventors: Asai, Kuniaki; Nitta, Itaru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a process for producing a carboxylic acid phenyl ester having such a high purity that is required in various fields. A process for producing a highly pure carboxylic acid phenyl ester by reacting an aromatic hydroxy compound with a carboxylic acid anhydride characterized by conducting the reaction in the presence of 0.01 part by weight or more of a tertiary amine per 100 parts by weight of the aromatic hydroxy compound.
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 October 7, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 7, 2013.
- 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.