Preparation of pyrazines
CA 2062149 A1 · Owner: Chen, Teh-Kuei · Inventors: Chen, Teh-Kuei
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Preparation of pyrazines, A process for the preparation of an alkyl pyrazine which comprises refluxing or refluxing with simultaneous sublimation of a mixture of an acyloin having the general formula: I, wherein R1 and R2 are either both methyl radicals or R1 is hydrogen and R2 is a saturated or unsaturated alkyl radical containing from 1 to 10 carbon atoms and an ammonium salt in water and isolating the product.
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 2, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 2, 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.