2-硝基苯胺合成苯并氧化呋咱反应的密度泛函研究

用密度泛函理论在B3LYP/6-31G(d,p)计算水平下研究了次氯酸钠氧化邻硝基苯胺生成苯并氧化呋咱的环氧化反应．考虑溶剂化效应对反应的影响，使用极化连续反应场模型进行几何优化．计算了该反应的两种可能反应通道，它们都是分步反应，反应通道A经历氧化、移氢、脱水和环化四步反应，在反应通道B中，氢氧化钠的OH^-首先进攻邻硝基苯胺的胺基H原子，生成邻硝基苯亚胺负离子．计算结果表明，在反应通道A是可行的反应通道，1个水分子辅助进行分子内脱水反应是速控步骤．

DFT Study of Benzofuroxan Synthesis Mechanism from 2-Nitroaniline via Sodium Hypochlorite

The oxidative cyclization reaction of 2-nitroaniline via sodium hypochlorite to yield benzo-furoxan is investigated by the hybrid density functional theory B3LYP/6-31G(d,p) method. Solvent effects are estimated with the polarizable continuum model to optimize structures. The title reaction is predicted to undergo two pathways, each of which is a stepwise process.Path A includes four steps, namely oxidization, H-attack, hydrolysis, and cyclization. Path B involves the nucleophilic attack of OH^- to the H atom of the N-H bond and the proton transfer to the N atom of amino group leading to the cleavage of the N-H single bond in the amino group. The calculated results indicate that path A is favored mechanism for the title reaction. Furthermore, it is rational for one water molecule serving as a bridge to assist in the hydrolysis step of Path A and our calculations exhibit that this process is the rate-determining step.