Process for the preparation of 3-pyridazones
CA 1111039 A · Owner: Hoechst Aktiengesellschaft · Inventors: Muller, Werner H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the disclosure:, Pyridazones are prepared by heating 4,5-dihydro-3pyridazones in the liquid phase in the presence of a dehydrogenation catalyst. The reaction temperature is in the range of from 150 to 350°C. The dehydrogenation catalyst contains a noble metal of subgroup 8 of the periodic table which is generally supported on a carrier. The reaction is preferably carried out in the presence of a solvent.
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 October 20, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 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.