Study On The Synthesis Of Ascorbic Acid Polyphosphate And Ascorbic Acid Phospate Magnesium

Ascorbyl polyphosphate and its magnesium salts are not only stable, but also good to play the role of ascorbic acid, so which are widely used in feed addivites, food nutrition additives, cosmetic whitening additives, medicine auxiliary preparation and so on.Along with the enhancement of people's living standards, ascorbyl polyphosphate and its magnesium salts has even greater demand for space. In view of the existing post- processing techniques of ascorbic acid phospate magnesium, the low energy consumption process of hydrolysis removal of protecting group in the acidic conditions was proposed in the article.1. Take ascorbic acid as raw material, sodium trimetaphosphat as phosphorylation agent, calcium chloride as catalyst, ascorbyl polyphosphate was prepared through esterifying reactions in polar solvement water system. Through single factor and orthogonal experiment, the ratio of raw materials (ascorbic acid to sodium trimetaphosphat), reaction temperature, amount of catalyst and pH of the solution on the yield of ascorbyl polyphosphate were discussed, and obtained the optimal reaction conditions:The results showed that the reaction temperature was 35℃, the mole ratio of ascorbic acid and sodium trimetaphosphat was 1.0:1.3, the mole ratio of ascorbic acid and calcium chloride was 1:0.15, pH of the solution was 9, at which experimental conditions, the yield of ascorbyl polyphosphate could be up to 76.58%.2. Take ascorbic acid as raw material, using the methods of group protection, frist reacting ascorbic acid with acetone to prepare 5,6-isopropylideneascorbic acid, then with phosphoryl chloride as phosphorylation agent, pyridine as catalyst, occurred phosphorylation reactions under alkaline conditions and removed protecting group through hydrolyzed in acidic conditions, then neutralized with alkali to prepare ascorbyl polyphosphate. Through single factor experiment, the ratio of raw materials (ascorbic acid to actone), reaction temperature and reaction time to the yield of intermediate product in the first step were investigated, the ratio of raw materials (5,6-isopropylideneascorbic acid to phosphoryl chloride), amount of catalyst and pH of the solution on the yield of ascorbyl polyphosphate in the second step were also discussed, and obtained a appropriate experimental conditions.The results showed that the reaction temperature was 25℃, the mole ratio of ascorbic acid and actone was 15:1, the mole ratio of ascorbic acid and the reaction time was 4h, at which experimental conditions, the yield of 5,6-isopropylideneascorbic acid could be up to 82.94%; the mole ratio of 5,6-isopropylideneascorbic acid and phosphoryl chloride was 1:1.4, the mole ratio of 5,6-isopropylideneascorbic acid and pyridine was 1:6, pH of the solution was 12, at which experimental conditions, the yield of ascorbyl polyphosphate could be up to 78.62%.According with the industry standards of feeding additives, the product was qualitative identified by way of infared (IR) spectrum and nuclear magnetic resonance (NMR).