N-乙酰-L-酪氨酸乙酯偶氮衍生物的合成及偶氮-腙互变异构性质

Synthesis and azo-hydrazone tautomerizm of N-acetyl-L-tyroaine ethyl ester azo derivatives

以N-乙酰-L-酪氨酸乙酯为原料,与6个取代芳胺重氮盐在碱性条件下发生偶合反应,合成了6个新型的N-乙酰-L-酪氨酸乙酯偶氮衍生物,结构通过IR、~1H NMR进行了表征.探讨了所合成化合物的偶氮式-腙式互变异构以及溶剂和pH对紫外可见光谱的影响.结果表明,溶质-溶剂相互作用会影响化合物在不同溶剂的λmax发生微小的变化,分子内和分子间氢键的作用影响较大.溶液pH会直接影响偶氮式-腙式的平衡构成,随着pH的增加,腙式在偶氮-腙互变异构平衡中的比例逐渐增加.这些偶氮化合物有望成为一类潜在的pH指示剂.

Six new azo compounds were synthesized by diazo-coupling reaction under basic condition with N-acetyl-L-tyrosine ethyl ester and six substituted aromatic amine diazonium salts as raw materials. The structures of the new azo compounds were confirmed by IR and ^1H NMR. The effects of various solvent and pH on the absorption spectra of the azo compounds were tested to study the azo-hydrazone tautomerizm phenomena. The results showed that the solute-solvent interactions in different solvents can affect minor changes in the compound λmax,and the hydrogen bonds play important influence. The proportion of hydrazone tautomer in azo-hydrazone taotomerizm equilibrium is rised with the increasing of pH. These new azo compounds could potentially be used as pH indicators.