槲皮素五乙酸酯的合成研究

Synthetic of five acetate quercetin

以槲皮素为原料,浓硫酸作催化剂,常温条件下与乙酸酐回流反应,静置过滤后,加入纯化水洗涤沉淀,反应过程中用薄层检测反应进度确保反应完全,然后进行分离、重结晶,得到晶体物质;光谱分析显示,紫外光谱中槲皮素的两个特征吸收峰均发生蓝移,这是形成新化合物共轭体系变化引起的;红外光谱中ν-OH峰消失,说明槲皮素的五个羟基发生了反应,νc=o位于1 776cm^(-1),说明槲皮素的羰基没有反应,νc-o位于1 124cm^(-1)、苯环骨架吸收峰数值上基本没有变化;核磁共振氢谱中3-OH、5-OH、7-OH、3′-OH、4′-OH上面的氢全部消失,说明与乙酸酐发生了酯化反应,同时,出现五组乙酰基的甲基峰;质谱中质荷比与目标化合物分子量完全吻合,由上述光谱分析得以确认化合物即为槲皮素五乙酸酯.槲皮素与乙酸酐,常温,在浓硫酸催化下,可以得到槲皮素五乙酸酯.

Using quercetin as raw materials,concentrated sulfuric acid as catalyst,the condition of normal temperature and acetic anhydride reflux reaction,after resting for the night,then add purified water to wash out precipitation,reaction process with thin layer detection reaction progress ensure complete reaction and separation,recrystallization,crystal material is obtained.Through the spectral analysis results showed that the UV spectra of quercetin in two characteristic absorption peaks are blue shifted,which iscaused by the change of the conjugate system of the new compound.;Infrared Spectrumν-OHpeak disappeared,it showed that the five hydroxyl groups of quercetin had a reaction,νc=o located1776cm-1,there was no reaction of the carbonyl group of quercetin.νC-O located1124cm-1,the absorption peak value of benzene skeleton did not change.Proton magnetic resonance spectroscopy in3-OH,5-OH,7-OH,3'-OH,4'-OH on hydrogen disappeared,that occurred in the esterification reaction with acetic anhydride,at the same time,five groups of acetyls’methyl peak.Mass Spectrometry mass to charge ratios of the target compound and molecular weight are in complete agreement.From the above analysis to confirm the spectra of compounds as quercetin pentaacetate,quercetin and acetic anhydride,room temperature,in the presence of concentrated sulfuric acid as catalyst can get quercetin pentaacetate.