Synthesis of (s)-3-(thien-2-ylthio) butyric acid analogs
CA 2040518 A1 · Owner: Merck & Co. Inc. · Inventors: Shinkai, Ichiro; Blacklock, Thomas J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
302/WHN28, 18116, TITLE OF THE INVENTION SYNTHESIS OF (S)-3-(THIEN-2-YLTHIO)BUTYRIC ACID ANALOGS, ABSTRACT OF THE DISCLOSURE, (S)-3-(thien-2-ylthio)butyric acid analogs are intermediates in the synthesis of the chiral (S,S)-5,6-dihydro-4-ethylamino-6-methyl-4H-thieno 2.3-bthiopyran-2-sulfonamide-7,7-dioxide and analogs thereof, topically effective carbonic anhydrase inhibitors useful in the treatment of ocular hypertension and glaucoma. They are prepared by condensation of 2-mercaptothiophene and (R)-(+)- .beta.-methyl-.beta.-propiolactone or an analog thereof.
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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 April 15, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 15, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 15, 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
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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.