Processes for the preparation of 5-hydroxy-3-oxopentanoic acid derivatives
CA 2339357 A1 · Owner: Nishiyama, Akira · Inventors: Nishiyama, Akira; Inoue, Kenji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Processes by which 5-hydroxy-3-oxopentanoic acid derivatives useful as intermediates of drugs can be prepared from inexpensive and easily available raw materials under noncryogenic conditions. Specifically a process for , preparing 5-hydroxy-3-oxopentanoic acid derivatives by making lithium amide act on a mixture of an acetic acid ester and a 3-hydroxypropionic acid derivative at a temperature of -20 ~C or above; and another process for preparing 5-hydroxy-3-oxopentanoic acid derivatives by treating a mixture of an acetic acid ester and a 3-hydroxypropionic acid derivative with a Grignard reagent and then making lithium amide act on the resulting mixture at a temperature of -20 ~C …
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 June 2, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 2, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 2022.
- 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.