Method of preparing .alpha.-l-aspartyl-l-phenylalaline methyl ester hydrochloride
CA 2069352 C · Owner: Kano, Mikiya · Inventors: Kishimoto, Shinichi; Kato, Toshihisa; Takeda, Hideo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
alpha.-L-Aspartyl-L-phenylalanine methyl ester hydrochloride is prepared by extracting N-formyl-.alpha.-L-aspartyl-Lphenylalanine methyl ester from a reaction mixture containing same in an organic solvent, with water at a temperature of from 40°C to 80°C, and allowing the resulting mixture to separate into an aqueous layer and an organic layer the, aqueous layer containing the N-formyl-.alpha.-L-aspartyl-Lphenylalanine methyl ester. The aqueous layer is isolated and the N-formyl-a-L-aspartyl-L-phenylalanine methyl ester contained therein is deformylated at a temperature of from 40°C to 80°C. .alpha.-L-Aspartyl-L-phenylalanine methyl ester is thereafter crystallized out in the form of its …
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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 May 25, 1992 and granted September 29, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 25, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 25, 2014.
- 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.