Process for the preparation of aromatic sulfonyl chlorides
CA 2019071 A1 · Owner: Hoechst Aktiengesellschaft · Inventors: Tronich, Wolfgang; Meier, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the disclosure Process for the preparation of aromatic sulfonyl chlorides, A process for the preparation of aromatic sulfonyl chlorides of the formula I, in which R1 R2 and R3 are identical or different and are hydrogen, fluorine, chlorine, bromine or iodine atoms alkyl(C1-C4), acetamido, nitro or carboxyl groups or R1, and R2 together form an aromatic or heteroaromatic ring having 5 or 6 ring members, which can be substituted by fluorine, chlorine, bromine or iodine atoms alkyl(C1-C4), acetamido, nitro or carboxyl groups by reaction of, aromatic compounds of the formula II in which R1, R2 and R3 have the abovementioned meanings with chlorosulfonic acid in excess or with …
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 June 15, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 15, 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.