One solvent process for preparation of esters of 3,5- dibromo-4- hydroxybenzonitrile
CA 1208655 A · Owner: Union Carbide Corporation · Inventors: Sheads, Richard E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Esters of 3,5-dibromo-4-hydroxybenzonitrile can be prepared in high yields from 4-cyanophenol in a single solvent. In this manner, the 3,5-dibromo-4hydroxybenzonitrile intermediate need not be isolated, and therefore the bromination and esterification reactions can be performed in one reactor. Preferably, the bromination is accomplished with bromine chloride in the presence of 1,1,2-trichloroethane followed by esterificaton with an acid chloride in the same solvent.
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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 29, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 29, 2003.
- 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.