A kinetic study of the reactions of potentially bioactive 2-amino-4-arylthiazoles with highly reactive 4,6-dinitrobenzofuroxan (DNBF) is reported herein in acetonitrile solution. The complexation reaction was followed by recording the UV–vis spectra with time at λ_max = 482 nm. Electronic effects of substituents influencing the rate of reaction have been studied using structure-reactivity relationships. It is shown that the Hammett plot relative to the reaction of DNBF with 2-amino-4-(4-chlorophenyl)thiazole exhibit positive deviation from the log k₁ versus σ correlation, while it showed excellent linear correlation in terms of Yukawa–Tsuno equation. It has be noticed that the nonlinear Hammett plot observed for 2-amino-4-(4-chlorophenyl) thiazole is not attributed to a change in rate-determining step but is due to nature of electronic effect of substituent caused by the resonance of stabilization of substrates. The second-order rate constant (k₁) relating to the bond C–C and C-N forming step of the complexation processes of DNBF with 4-substituted-aminothiazoles and 2-amino-5-methyl-4-phenylthiazole, respectively, is fit into the linear relationship log k = s_N (N + E), thereby permitting the assessment of the nucleophilicity parameter (N) of the 2-amino-4-arylthiazoles of the range (4.90 < N < 6.85). 2-amino-4-arylthiazoles is subsequently ranked by positioning its reactivity on the general nucleophilicity scale developed recently by Mayr and coworkers (2003) leading an interesting and a direct comparison over a large domain of π-, σ -, and n-nucleophiles. The global electrophilicity/nucleophilicity reactivity indexes of the 2-amino-4-arylthiazoles have been investigated by means of a density functional theory (DFT) method. .

本文报道了在乙腈溶液中可能具有生物活性的2-氨基-4-芳基噻唑与高反应性4,6-二硝基苯并呋喃（DNBF）反应的动力学研究。络合反应后，随时间记录在_λmax  = 482 nm处的UV-vis光谱。已经使用结构反应性关系研究了取代基影响反应速率的电子效应。结果表明，相对于DNBF与2-氨基-4-（4-氯苯基）噻唑的反应，Hammett图相对于log k ₁表现出正偏差。与σ相关，而在Yukawa–Tsuno方程方面显示出极好的线性相关。已经注意到，对于2-氨基-4-（4-氯苯基）噻唑观察到的非线性哈米特图不归因于速率确定步骤的变化，而是归因于由稳定共振引起的取代基的电子效应的性质。基板。拟合分别与DNBF与4-取代-氨基噻唑和2-氨基-5-甲基-4-苯基噻唑络合过程的键C–C和CN形成步骤有关的二级速率常数（k ₁）取线性关系log k  = s _N（N  +  E），从而可以评估亲核参数（Ñ）的范围内（4.90 <的2-氨基-4- arylthiazoles的 Ñ  <6.85）。随后将2-氨基-4-芳基噻唑的反应性定位在Mayr和他的同事（2003年）最近开发的一般亲核性等级上，从而在π-，σ-和n-亲核体的大范围内进行了有趣而直接的比较。。通过密度泛函理论（DFT）方法研究了2-氨基-4-芳基噻唑的整体亲电/亲核反应性指数。。