Process for preparing 2-anilinoacridones
CA 2237077 A1 · Owner: Jaffe, Edward Ephraim · Inventors: Jaffe, Edward Ephraim; Gerzevske, Kevin Rodney
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for the preparation of optionally 2-anilinoacridones from optionally substituted 2,5-dianilinoterephthalic acids comprises:, (a) cyclizing 2,5-dianilinoterephthalic acid to give an intermediate product mixture which contains a major portion of a 2-anilino-3-carboxyacridone and a minor portion of a quinacridone;, (b) combining said intermediate product mixture with a solvent which dissolves the 2-anilino-3-carboxyacridone at elevated temperatures but does not dissolve the quinacridone; (c) decarboxylating the 2-anilino-3-carboxyacridone in the mixture from step (b) at elevated temperatures to yield a product slurry comprising a solid quinacridone and a 2-anilinoacridone …
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 May 7, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 7, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2020.
- 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.