Preparation of maleimides and dimaleimides
CA 1094080 A · Owner: E. I. Du Pont De Nemours And Company · Inventors: Orphanides, Gus G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the preparation of maleimides and dimaleimides in high yield, wherein the first step maleic anhydride and a suitable primary amine or diamine are contacted at about 30-60°C in the presence of a simple cheap organic solvent; and in the second step the thusformed intermediate is cyclized, without prior isolation at 45-60°C in the presence of a lower fatty acid anhydride a tertiary amine having a pKa of at least 10 and of a salt of magnesium, lithium, manganese(II), or cobalt(II) soluble in the liquid reaction medium to the extent of at least 0.2 weight percent. Alternatively, the tertiary amine can be added in the first step. The product maleimide or dimaleimide normally can be …
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 January 20, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 20, 1998.
- 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.