A green non-acid-catalyzed process for direct N=N-C group formation: comprehensive study, modeling, and optimization

The aim of this work is to introduce, model, and optimize a new non-acid-catalyzed system for a direct NN-C bond formation. By reacting naphthols or phenol with anilines in the presence of the sodium nitrite as nitrosonium ( source and triethylammonium acetate (TEAA), a NN-C group can be formed in non-acid media. Modeling and optimization of the reaction conditions were investigated by response surface method. Sodium nitrite, TEAA, and water were chosen as variables, and reaction yield was also monitored. Analysis of variance indicates that a second-order polynomial model with F value of 35.7, a P value of 0.0001, and regression coefficient of 0.93 is able to predict the response. Based on the model, the optimum process conditions were introduced as 2.2 mmol sodium nitrite, 2.2 mL of TEAA, and 0.5 mL at room temperature. A quadratic (second-order) polynomial model, by analysis of variance, was able to predict the response for a direct N=N-C group formation. Predicted response values were in good agreement with the experimental values. Electrochemistry studies were done to introduce new Michael acceptor moieties. Broad scope, high yields, short reaction time, and mild conditions are some advantages of the presented method.