C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
C07D263/02—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings
C07D263/30—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
C07D263/34—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
New process for the industrial synthesis of tetraesters of 5-[bis(carboxymethyl)amino]-3carboxymethyl-4-cyano-2-thiophenecarboxylic acid, and application to the synthesis of bivalent salts of ranelic acid and their hydrates.