L-抗坏血酸棕榈酸酯的化学合成工艺优化

Studies on the synthesis of L-ascorbic palmitate by chemical method

详细研究了一种以L-抗坏血酸和棕榈酸为原料,浓硫酸为催化剂和溶剂,直接酯化合成新型抗氧化剂L-抗坏血酸棕榈酸酯的改进方法。通过实验改进了产物的精制方法,选用了更适宜的重结晶及洗涤试剂。同时考察了反应温度,反应时间及L-抗坏血酸与棕榈酸的物质的量比等关键因素对L-抗坏血酸棕榈酸酯产率的影响,确定了合成L-抗坏血酸棕榈酸酯的最佳工艺条件为:L-抗坏血酸与棕榈酸以物质的量比1∶1.35的比例,于25℃的反应温度下,在98%浓硫酸中反应40h后,反应混合物经过冰水洗涤、甲苯重结晶、石油醚洗涤,产率可达86.3%。该方法后处理工序简单,分离效果好,产率高,生产成本相对较低,更适宜工业化生产。合成的产品经熔点、红外光谱及质谱进行鉴定,符合GB16314-1996标准。

In this paper,the improved synthesis method of L-ascorbyl palmitate was studied by the reaction of L-ascorbic acid with palmitic acid in the presence of concentrated sulfuric acid as catalyst.The more suitable recrystalization and washing solvent were selected.Moreover,the optimized process conditions,such as the reaction temperature,the reaction time and the mol ratio of ascorbic acid to palmitic acid were determined.In the presence of 5 mL 98% H2SO4as catalyst and solvent,the reaction of 1 mol L-ascorbic acid with 1.35 mol palmitic acid occurred smoothly at 25℃.After 40h,the isolated yield reached 86.3%.The practical performance of the new process is simple and convenience,so this new technology can be applied to the batch production of L-ascorbyl palmitate.In addition,the product was identified by melting point,IR,and mass spectra,which indicate the data meet the standard of GB16314-1996.