Process for the preparation of 2-amino-4,5,3',4'-tetramethoxybenzophenone
CA 2264402 A1 · Owner: Heinzmann, Etienne · Inventors: Werbitzky, Oleg; Brieden, Walter; Heinzmann, Etienne
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
2-amino-4,5,3',4'-tetramethoxybenzophenone of the formula: (see fig. I), is prepared by mononitration of 3,3',4,4'-tetramethoxybenzophenone using nitric, acid in the presence of acetic acid and subsequent reduction of the nitro group. The compound is an intermediate in the synthesis of active ingredients against rheumatoid arthritis.
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 March 4, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 4, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 4, 2021.
- 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.