N-硬脂酰基亮氨酸的合成

Synthesis of N-Stearyl Leucine

采用酰氯化反应与缩合反应两步法合成N -硬脂酰基亮氨酸。以硬脂酸和亚硫酰氯为原料 ,n(硬脂酸 )∶n(亚硫酰氯 ) =1∶1 .5 ,在 80℃下冷凝回流 6h酰氯化反应合成硬脂酰氯 ,硬脂酰氯经减压蒸馏收集 1 70～2 0 0℃的馏分得到。硬脂酰氯收率为 65 %。硬脂酰氯再与亮氨酸的氢氧化钠溶液在冰水浴中进行Schotten -Baumann缩合反应制得N -硬脂酰基亮氨酸。缩合反应最佳工艺条件是反应溶液pH值控制为 9.0。反应后滴加1mol/L盐酸至pH =5 .0～ 6.0 ,加入正己烷使N -硬脂酰基亮氨酸处于水层中 ,分离并蒸干水层溶液得含NaCl的混合物。用无水乙醇萃取混合物 ,萃取液蒸干得产物。N -硬脂酰基亮氨酸收率为 75 %

N-Stearyl Leucine is synthesized by two step reactions, the acylation and condensation reaction. In the first step, stearyl chloride is made by stearic acid and thionyl chloride , n(stearic)∶n(thionyl chloride)=1∶1.5 ,at the reaction temperature 80℃and the reaction time of 6 hours. Stearyl chloride is gotten by collecting the fraction from 170℃ to 200℃in the reduced pressure distillation. The yield is 65%. In the second step, stearyl chloride reacts with Leucine to form N-Stearyl Leucine by Schotten-Baumann condensation reaction at the reaction temperature 0℃. The pH value is 9.0 for the optimum reaction. After reaction, pH values are adjusted to 5.0～6.0 by adding HCl to the reaction liquor . N-Stearyl Leucine goes into water by adding n-hexane. After separating the water and oil layer, dry the water part, get the mixer of N-Stearyl Leucine and sodium chloride. The mixer is extracted by anhydrous ethanol. N-Stearyl Leucine is dried by evaporating the anhydrous ethanol solution. The yield is 75%.