Process for the preparation of peri-dichalcogeno polycyclic aromatic compounds
CA 2061901 A1 · Owner: Mayer, Carl W. · Inventors: Mayer, Carl W.; Hauenstein, Kurt
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
FM/6-18583/A, Process for the preparation of peri-dichalcogeno polycyclic aromatic compounds Abstract of the Disclosure, A process for the preparation of peri-dichalcogeno polycyclic aromatic compounds by preparing in a first step, in an amidic solvent an alkali metal sulfide, selenide or telluride which, in a second step, is reacted with a peri-halogeno aromatic compound which, process comprises reacting in said first step an alkali metal base with elemental sulfur selenium or tellurium at elevated temperature.
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 March 13, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 13, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 13, 2014.
- 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.