| 摘要 |
<p>of the disclosure: A process for the manufacture of butanedicarboxylic acid esters, whereina) an aqueous cobalt salt solution is treated with carbon monoxide and hydrogen in the presence of active charcoal,b) the resulting aqueous solution is extracted with butadiene or with a hydrocarbon mixture containing butadiene,c) the butadiene, or butadiene/hydrocarbon mixture, containing cobalt carbonyl hydride, cobalt carbonyl and butenyl-cobalt tricarbonyl, is reacted with carbon monoxide and an excess of an alkanol of 1 to 4 carbon atoms in the presence of a tertiary nitrogen base,d) the tertiary nitrogen bases contained in the resulting reaction mixture are removed from the latter to the extent of leaving from 0.1 to 0.3 mole per mole of pentenoic acid ester, excess hydrocarbons are also removed, the pentenoic acid ester remaining in the reaction mixture is reacted with carbon monoxide and an alkanol of 1 to 4 carbon atoms, and thereafter excess alkanol and free nitrogen base are distilled off ande) the residual reaction mixture, containing cobalt catalysts, butanedicarboxylic acids and by-products is treated with an oxidizing agent in an aqueous acid medium and the mixture is separated into an organic phase, from which butanedicarboxylic acid esters are isolated by distillation, and an aqueous phase containing cobalt salts, which phase is extracted with a water-immiscible solvent.</p> |
