Method for producing o-chloromethyl benzenecarbonyl chlorides
CA 2393978 A1 · Owner: Stamm, Armin · Inventors: Kneuper, Heinz-Josef; Wolf, Bernd; Gotz, Roland
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method for producing o-chloromethyl benzenecarbonyl chlorides of formula (I), wherein R1-R4 can be the same or different and stand for hydrogen, C1-C4-alkyl, halogen or trifluoromethyl by converting , benzocondensed lactones of formula (II) wherein R1-R4 have the aforementioned meaning, with gaseous or liquid phosgene and the dimers or trimers thereof. The inventive method is characterised in that the conversion is carried out in the presence of catalytical amounts of a Lewis acid and catalytical amounts of a phosgenation catalyst.
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 27, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 27, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 27, 2022.
- 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.