公开(公告)号：US20060058550A1

公开(公告)日：2006-03-16

申请号：US10534334

申请日：2003-11-07

Applicant: Thomas Domschke ,  Martin Merger ,  Georg Grobmann ,  Tillmann Faust

Inventor： Thomas Domschke ,  Martin Merger ,  Georg Grobmann ,  Tillmann Faust

IPC: C07C69/66

CPC classification number: C07H7/027 ,  Y02P20/127

Abstract: The invention relates to a method for producing 2-keto-L-gulonic acid-C4-C10 alkyl ester by esterifying 2-keto-L-gulonic acid (KGS) with an unsaturated, branched or unbranched C4-C10 alcohol. The inventive method is characterized by the fact that an aqueous KGS solution is reacted with a C4-C10 alcohol up to an esterification degree of 20 to 70 percent in a pre-esterification process carried out under acidic catalysis conditions; and the obtained product is dehydrogenated with an unsaturated, branched or unbranched C4-C10 alcohol in a continuous rectification device, whereby the esterification reaction continues, n-butanol preferably being used as the alkyl alcohol. In a preferred embodiment, the aqueous KGS solution is concentrated up to or beyond the limit of solubility prior to the esterification process, preferably by catalyzing a homogeneous or heterogeneous catalyst, especially sulfonic acid, at temperatures of 50 to 120 ° C. In another embodiment, the produced KGS ester is reacted in one or several additional steps so as to obtain L-ascorbic acid.

Abstract translation: 本发明涉及通过酯化2-酮-L-古洛糖酸（KGS）制备2-酮-L-古洛糖酸-C 4 -C 10烷基酯的方法 ）与不饱和，支链或非支链C 4 -C 10醇。 本发明的方法的特征在于，将KGS水溶液与C 4 -C 10 - 醇反应，直到酯化程度为20至70％ 在酸性催化条件下进行酯化过程; 并将得到的产物用连续精馏装置中的不饱和支链或非支链C 4 -C 10醇脱氢，由此继续进行酯化反应，正丁醇优选为 用作烷基醇。 在优选的实施方案中，在酯化过程之前，优选通过在50至120℃的温度下催化均相或多相催化剂，特别是磺酸，将KGS水溶液浓缩至或超过溶解度的极限。在另一个实施方案中 ，所制备的KGS酯在一个或几个附加步骤中反应，以获得L-抗坏血酸。