Control of isomer distribution in a chlorination process
CA 2026360 C · Owner: Dow Agrosciences Llc · Inventors: Garibaldi, Mark L.; Dietsche, Thomas J.; Helling, Richard K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The relative amounts of 5,6-dichloro-2-(trichloromethyl) pyridine and 3,6-dichloro-2-(trichloromethyl)pyridine obtained in the chlorination of, 2-chloro-6-(trichloromethyl)pyridine in the liquid phase at temperatures of 160°C to 220°C and in the presence of a metal halide catalyst, such as ferric chloride are, controlled by regulating the amount of hydrogen chloride present in the system, adding hydrogen chloride to obtain a mixture enriched in 5,6-dichloro-2-(triohloromethyl) pyridine or removing hydrogen chloride usually, by passing excess chlorine or an inert gas through the system, to obtain a mixture enriched in 3,6-dichloro-2-(trichloromethyl)pyridine.
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 September 27, 1990 and granted January 30, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 27, 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.