Process for producing phthalide
CA 1080726 A · Owner: Dynamit Nobel Aktiengesellschaft · Inventors: Amort, Jurgen; Englander, Fritz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is concerned with a process for the hydrogenolysis of 3-chlorophthalide wherein the formation of undesired by-products is substantially decreased and yields of phthalide of over 90% are obtained. This process which is carried out in the presence of a precious metal catalyst is characterized in that 3-chlorophthalide is subjected to hydrogenolysis in the absence of HCl-acceptors at a temperatures ranging between 50 and 250°C, preferably between 80 and 130°C.
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
- Granted July 1, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 1, 1997.
- 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.