Process for the preparation of 1-aryl-5-amino-pyrazoles
CA 1313375 C · Owner: Gallenkamp, Bernd · Inventors: Gallenkamp, Bernd; Arold, Hermann
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 a 1-aryl-5amino-pyrazole of the formula, in which Ar is in each case optionally substituted phenyl or pyridyl comprising reacting an arylhydrazine of the formula Ar-NH-NH2, with acrylonitrile of the formula CH2=CH-CN, in a first stage in the presence of a diluent at a temperature between about 20°C and 100°C to form the arylhydrazine derivative of the formula Ar-NH-NH-CH2-CH2-CN, and, in a second stage contacting such derivative with an Le A 24 464 -U S, oxidizing agent in the presence of a base at a temperature between about 0°C and 60°C, thereby to effect oxidation and cyclization. The products are known intermediates for herbicides and insecticides.
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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 February 2, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 2, 2010.
- 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.