Fused thiophene derivatives, their production and use
CA 2036618 C · Owner: Naka, Takehiko · Inventors: Naka, Takehiko; Morimoto, Akira; Nishikawa, Kohei
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel fused thiophene derivatives of the formula (I):, (see formula I), wherein W is, (see formula II) or (see formula III) R1 and R2 are each. H, halogen, cyano, nitro acylamino, or a, hydrocarbon residue; R3 is H optionally substituted alkyl or, alkenyl or -COD wherein D is H, alkoxy, hydroxy halogen, or optionally substituted amino; R4 is H halogen or nitro;, R5 is a residue capable of forming or convertible into an anion; R6 is H or optionally substituted alkyl or alkenyl; R7 is a hydrocarbon residue; A is a bond or a spacer; and n is 1 or 2; have potent angiotensin II antagonist activity and antihypertensive activity, thus being useful as therapeutic agents for treating circulatory …
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 February 19, 1991 and granted October 29, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 19, 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.