Process for the preparation of 5-amino-3-chlorosulfonyl- -1,2,4-triazole
CA 2029316 C · Owner: The Dow Chemical Company · Inventors: Krauss, Richard C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
5-Amino-3-chlorosulfonyl-1,2,4-triazole is prepared by the chlor-oxidation of 5-amino-3-mercapto- -1,2,4-triazole. The process is characterized by the preformation of disulfide from the mercaptan prior to treatment with chlorine. The 5-amino-3-chlorosulfonyl- -1,2,4-triazole reaction mixture can be directly reacted with substituted anilines to prepare N-(3-(((aryl)ami no)sulfonyl)-1H-1,2,4-triazol-5-yl)amines which are useful intermediates for the manufacture of herbicides.
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
- Filed November 5, 1990 and granted November 28, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 5, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 5, 2012.
- 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.