Process for the production of substituted vinylbenzenes
CA 2080048 A1 · Owner: Warm, Aleksander · Inventors: Laffan, David; Warm, Aleksander
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed for the production of substituted vinylbenzenes of the general formula: (I), wherein R is a lower alkyl group having 1 to 4 C atoms R1, is hydrogen or an acetyl group and R2 is hydrogen a lower, alkyl group having 1 to 4 C atoms or a benzyl group. A trialkylhydroquinone is cyclized with an aldehyde to form an acetal and the latter is pyrolized to produce the end product. The substituted vinylbenzenes are valuable intermediate products in the synthesis of antioxidants.
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, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 7, 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.