Process for the preparation of diphosphonic acids and salts thereof
CA 2058905 A1 · Owner: Guainai-Ricci, Giuseppe · Inventors: Rosini, Sergio; Guainai-Ricci, Giuseppe
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the preparation of diphosphonic acids of the formula, and salts thereof, wherein 2 ? n ? 8 obtained by reacting, the corresponding aminocarboxilic acid with phosphorous acid and phosphorus trihalide characterized in that the reaction is conducted under relatively large excess of phosphorous acid and phosphorus trihalide.
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 January 7, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 7, 2014.
- 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.