Method for increasing the alpha to beta ratio in an aspartame coupling reaction
CA 2058932 C · Owner: Nutrasweet Company (The) · Inventors: Gelman, Yefim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved coupling step of an .alpha.-APM manufacturing process is disclosed. The solvents in the coupling step are adjusted in one of two ways to improve the .alpha.- to .beta.- isomer ratio of the product of the coupling step, .alpha..beta. protected L-aspartyl-L-phenylalanine or lower alkyl ester thereof. In one manner the solvent may, comprise an increased concentration of a carboxylic acid such as acetic acid alone. In the other manner one or more additional, solvents along with a carboxylic acid such as acetic acid in conventionally known concentrations are used.
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 March 6, 1991 and granted August 25, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 6, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 6, 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.