VERFAHREN ZUR HERSTELLUNG DER 3-0(BETA-CARBOXYPROPIONYL)-18BETA-GLYCYRRHETINSAEURE

摘要

A two-step method for the preparation of 3-0-(beta-carboxypropionyl-18-beta-glycyrrhetic acid (carbenoxolone) is disclosed, which comprises the steps of condensing beta-glycyrrhetic acid with anhydrous beta-carbobenzyloxypropionic acid (or a derivative thereof such as its chloride or anhydride), the result being 3-O-(beta-carbobenzyloxypropionyl)-11-oxo-18-beta-olean-12-en-30-oic acid, the latter compound being then debenzylated with hydrogen under normal temperature and pressure conditions, in an alcoholic solvent (alcohols having from C1 to C5) and in the presence of catalytic amounts of a noble metal (e.g. palladium), thus obtaining the expected compound.