Novel mrthylenebisphosphonic acid derivatives
CA 2098734 A1 · Owner: Leiras Oy · Inventors: Pohjala, Esko; Nupponen, Heikki; Vepsalainen, Jouko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to novel methylenebisphosphonic acid ester amide derivatives of general formula (I) in which formula W1, W2, W3 and W4 are independently the group OR1 or the group NR2R3 wherein R1, R2 and R3 independently are hydrogen or straight or branched, optionally unsaturated C1-C22-alkyl, optionally substituted, optionally unsaturated C3-C10-cycloalkyl, aryl, aralkyl or silyl SiR3 or the groups R2 and, R3 form together with the adjacent nitrogen atom a 3 to 10-membered saturated, partly saturated or aromatic heterocyclic ring wherein in addition to the nitrogen atom there may be one or two, heteroatoms from the group N O and S, provided that in formula (I) at least one of the …
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 December 18, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 18, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 18, 2013.
- 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.