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Preparation of ascorbic acid 2-phosphate and of 5, 6- isopropylideneascorbic acid and potassium magnesium l-ascorbate 2- phosphate as an advantageous salt of l-ascorbic acid 2- phosphate
Preparation of ascorbic acid 2-phosphate and of 5, 6- isopropylideneascorbic acid and potassium magnesium l-ascorbate 2- phosphate as an advantageous salt of l-ascorbic acid 2- phosphate
Ascorbic acid 2-phosphate is prepared by reacting ascorbic acid or an ascorbic acid derivative with POCl.sub.3 in the presence of a tertiary amine in a suitable aqueous solvent at from -10 to 25 C. while maintaining a pH of about 8-13.5 with KOH during the entire phosphorylation reaction and then isolating the ascorbic acid 2-phosphate, by a process in which an aqueous solution of a magnesium compound is added to the reaction mixture obtained in the phosphorylation, without prior treatment with an ion exchanger, until the formation of crystalline KMg PO.sub.4 is complete, the KMgPO.sub.4 which is crystallized out is separated off, the resulting filtrate is evaporated down at a pH of from 6 to 11 and/or from 0.1 to 5 times the amount, based on the evaporated filtrate, of a lower primary alkanol or acetone is added and the stirred mixture is cooled until KCl has completely crystallized out, and the ascorbic acid phosphate is isolated in a conventional manner from the reaction solution obtained by separating off KCl and substantially freed from inorganic salts. It is particularly advantageous if the ascorbic acid 2-phosphate is isolated in the form of the novel potassium magnesium ascorbate 2-phosphate, which is also claimed.PPThe process is particularly advantageous if the ascorbic acid derivative used is 5,6-isopropylideneascorbic acid which has been obtained by reacting ascorbic acid with acetone in the presence of oleum. The process is particularly important for the preparation of L-ascorbic acid 2-phosphate.
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机译:抗坏血酸2-磷酸酯是通过在叔胺存在下,在合适的水性溶剂中于-10至25°C下使抗坏血酸或抗坏血酸衍生物与POCl.3反应,并保持pH值约为8来制备的。在整个磷酸化反应过程中用KOH处理13.5,然后通过将镁化合物的水溶液添加到在磷酸化中获得的反应混合物中的过程中分离出抗坏血酸2-磷酸,而无需事先用离子交换剂处理,结晶的KMg PO 4的形成完成,结晶出的KMg PO 4分离出来,所得滤液在6至11的pH和/或0.1至5倍的pH下蒸发。基于蒸发的滤液,加入适量的低级伯烷醇或丙酮,并将搅拌的混合物冷却至KCl完全结晶,然后按常规方式从反应液中分离出抗坏血酸磷酸酯。通过分离出KCl而获得并基本上不含无机盐。如果将抗坏血酸2-磷酸酯以新颖的抗坏血酸钾镁2-磷酸酯的形式分离出来,则是特别有利的,该方法也是如此。如果所用的抗坏血酸衍生物为5,则该方法特别有利。通过在发烟硫酸存在下抗坏血酸与丙酮反应制得的1,6-异亚丙基异抗坏血酸。该方法对于制备L-抗坏血酸2-磷酸酯特别重要。
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