Process for preparing benzofuran derivatives
CA 1066702 A · Owner: Fisons Limited · Inventors: Harris, John F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Compounds of the formula:, I wherein R1 and R2 may be the same or different and each is selected from the group consisting of hydrogen an alkyl group, and, together, an alkylene chain; and R3 is an alkyl group; R4 is selected from the group consisting of an alkyl group and with, R3 and the N atom, a heterocyclic ring or derivatives thereof are prepared by reacting benzoquinone with an enamine R1R2C=CH-NR3R4 in the presence of a compound of formula R1R2CHCHO. The product contains a lower proportion of hydroquinone impurity and finds use in the preparation of herbicides.
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 November 20, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 20, 1996.
- 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.