Pictet-spengler reaction for the synthesis of tetrahydroisoquinolines and related heterocyclic compounds
CA 2266357 C · Owner: Watson, Timothy James-Norman · Inventors: Watson, Timothy James-Norman
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A commercial scale process for the production of tetrahydroisoquinolines and related heterocyclics by reaction, in mildly acidic conditions of aryl N-, sulfonylethylamines in the presence of suitable Lewis acid and a compound , capable of in situ generation of formaldehyde. The process is further characterized by formaldehyde being generated by the reaction of the Lewis acid upon the formaldehyde generating agent instead of being present as an , initial reactant. The process further avoids the presence of initial water which destroys the Lewis acid before it can act upon the formaldehyde generating agent.
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 August 4, 1997 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 4, 2019.
- 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.