Process for the preparation of vincaminic acid esters
CA 1261840 A · Owner: Richter Gedeon Vegyeszeti Gyar Rt · Inventors: Szabo, Lajos; Kalaus, Gyorgy; Visky, Gyorgy
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
23305-866, Abstract, The invention relates to a new process for the preparation of apovincaminic acid esters. More particularly the, invention concerns a process for preparing racemic and optically active vincaminic acid esters of the formula (I) (I), in which, R1 and R2 independently stand for alkyl having from one to 6 carbon atoms, and 14-epimers thereof. According to the invention an octahydroindolo-2,3alquinolizine-oxime ester of the formula (II) (II), 23305-866, in which R1 and R2 have the same meaning as defined above is, reacted with an aqueous solution of sulphurous acid or a salt thereof at a temperature of 80 to 110°C and the 14-epimeric mixture obtained is epimerized or …
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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
- Granted September 26, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 26, 2006.
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Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.