Process for the preparation of sulfonyl ureas
CA 1051026 A · Owner: Akzona Incorporated · Inventors: Zengel, Hans-Georg; Bergfeld, Manfred; Lischka, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An arylene-bis-sulfonyl urea of the formula: R'-SO2-N-CO-NH-Ar-NH-CO-N-SO2-R'2- 2 Me+ wherein Ar is arylene, R' is amino, an aliphatic residue having 1 to 20 carbon atoms, a cycloaliphatic residue having 4 to 10 carbon atoms an, aromatic residue, an alkyl-aromatic residue or a heterocyclic residue, and, Me+ is a sodium or potassium ion is prepared by reacting a dicarboxylic acid-N,N'-dichloramide of the formula: CL-NH-CO-Ar-CO-NH-Cl, with a sulfonic acid amide of the formula: R'-SO2-NH2, in a mixture of dimethylformamide and water in the presence of excess al-, kali hydroxide and at a temperature between 10° and 50°.
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 March 20, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 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.