申请人:——
公开号:US04867901A1
公开(公告)日:1989-09-19
There is disclosed herein improved processes for the preparation of mixtures of alkali metal salts of 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylate and alkali metal salts of 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylate wherein D,L-tartaric acid is employed and recovered by lowering the pH of the reaction medium to within the range of from about 7 to about 9.5. At the reduced pH calcium D,L-tartrate precipitates and is easily separated. The recovered tartrate may be recycled to the synthesis reaction to prepare further product.
本文披露了改进的工艺,用于制备1-羟基-3-氧杂-1,2,4,5-戊烷四羧酸盐和3,6-二氧杂-1,2,4,5,7,8-辛烷六羧酸盐的混合物,其中使用D,L-酒石酸,并通过将反应介质的pH降至约7至约9.5的范围内来回收它。在降低的pH值下,钙D,L-酒石酸会沉淀并易于分离。回收的酒石酸盐可循环使用于合成反应以准备进一步的产品。