Process for preparing aromatic fluorides
CA 1289152 C · Owner: Mallinckrodt, Inc. · Inventors: Cantrell, Gary L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process is disclosed for preparing aromatic fluorides by diazotization-fluorination in hydrogen fluoride wherein the diazotized reaction mixture includes an oxidizing agent such as nitrosonium ion from excess diazotization agent. The improvement includes prior to, decomposing the diazonium fluoride adding to the, diazotized reaction mixture a member selected from hydrazine, aromatic hydrazine, semi-carbazide thio-, semicarbazide, acid salts thereof sulfur dioxide, sodium, sulfite, and sodium bisulfite to remove at least a portion of the oxidizing agent. Urea was found to be ineffective.
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 September 17, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 17, 2008.
- 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.