Processes for preparing 1,5-benzothiazepine derivatives
CA 2015179 C · Owner: Nakao, Akio · Inventors: Ikeda, Yasuji; Nakao, Akio; Nate, Hiroyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed a process for preparing 1,5-benzothiazepine derivatives represented by the formula: (I), wherein one of R1 and R2 is a lower alkyl group or halogen atom, and the other is hydrogen atom R3 is a, lower alkyl group or a lower alkoxy group which comprises subjecting a propionic acid compound represented by the formula (II):, (II) wherein R1, R2 and R3 have the same meanings as defined above, and R4 represents hydrogen atom or an ester residue, to intramolecular ring closing reaction in the presence of a sulfonic acid compound represented by the formula (III): R5SO3H (III), wherein R5 represents a lower alkyl group or a substituted or unsubstituted phenyl group.
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 April 23, 1990 and granted December 10, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 23, 2012.
- 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.