Sialic acid derivative with active ester groups
CA 2003984 A1 · Owner: Yoshimura, Shoji · Inventors: Tanaka, Makoto; Yoshimura, Shoji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sialic acid derivative with active ester groups expressed with the formula I, I , Where R1 denotes hydrogen or acetyl group R2, hydrogen or lower alkyl group, R3 C2H4 C3H6 or C2H2, R4, hydroxyl group, residue left after removing hydrogen from the alcohol portion of active ester or alkyloxycarbonyloxy group, Ac acetyl group Ph phenyl, group, X oxygen or sulfur. This sialic acid derivative has high reactivity because it has active ester groups in molecules and can be used as raw material or intermediate for synthesis of various sialic acid derivatives.
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, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 27, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 27, 2011.
- 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.