PROCESS FOR OBTAINING PHARMACEUTICALLY ACTIVE ALKALOID ESTERS OF THE EBURNAMINE TYPE

• Main Authors: KISFALUDY LAJOS, SZPORNY LASZLO, SZASZ KALMAN, KARPATI EGON, LORINCZ CSABA
• Format: Patent
• Language: English
• Published: 13.11.1981
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; METALLURGY; ORGANIC CHEMISTRY; PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES

A process for the preparation of pharmaceutically active eburnamine type alkaloid esters of the general formula (I) **(See formula)** in which (see formula) represents a group (see formula), R represents a C1-6 alcosicarbonyl group optionally substituted with a hydroxyl group or with a halogen atom, or also an alkenyloxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl group or an acylated primary alcohol group, or quaternary salts or derivatives thereof, wherein a) an apovincaminic acid or vincaninic acid salt is reacted with a C1-6alkyl halide, a C1-6alkenyl halide, a C1-6alkyl halide substituted with one or more halogen or hydroxyl groups, an aralkoxy halide or aryl halide, or with the corresponding sulfates, or with diazomethane, or b) apovincaminic acid or vincaminic acid is esterified with a C1-6 alcohol in the presence of one or more catalysts, preferably in the presence of ammonia, mineral or organic acids, or aliphatic or aromatic sulfonic acids, or c) apovincamine or vincamine is reacted with an alkali metal alcoholate, or d) apovirca acid is reacted minico or vincaminic acid, or, respectively, apovincamine or vincamine, with an ester of a C1-6 carboxylic acid, or e) the apovincaminic acid or vincaminic acid, or, respectively, the apovincamine or vincamine, is converted into the corresponding hydroxyl derivative by reacting them with a reducing agent (preferably with one or more alkali metal hydrides), and the obtained compound is esterified with an anhydride or halide of an aliphatic carboxylic acid or an aromatic carboxylic acid, and, if desired, the thus obtained compounds of the general formula (I) are converted into their acid addition salts or quaternary salts by reacting them with a mineral or organic acid or with an alcohol halide, respectively; and finally, if desired, the salts obtained are converted to the free bases, and the free bases are converted to other salts thereof. (Machine-translation by Google Translate, not legally binding)