Process for the preparation of 6-o-methyl erythromycin a using 9-hydroxy erythromycin derivatives
CA 2615701 A1 · Owner: Tien, Jien-Heh J. · Inventors: Ku, Yi-Yin; Lee, Elaine C.; Riley, David A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The claimed invention provides a novel method of preparing 6-O-methyl erythromycin A. The process comprises the steps of reducing the 9-keto group of erythromycin A to form a 9-hydroxy erythromycin A, protecting the 9-, 2'-, and/or 4"-hydroxyl groups of erythromycin A, selectively methylating the 6-position of the 9-hydroxy erythromycin A derivative, deprotecting the hydroxyl groups and oxidizing the 9-hydroxyl to afford 6-O-methyl erythromycin A.
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 November 17, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 17, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 17, 2020.
- 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.