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چکیده
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Ethinyl anilines, as a group of heteroaryl acetylenes, are widely used in materials science, especially as a strong electron donor for applications in optoelectronic devices and their ability to the formation of a diazonium compound and doing the polymerization reaction [1-2]. Also, these compounds as primary amines play a pivotal role in the synthesis of various substrates [3-4]. In this study electrochemical oxidation of 4-ethynylaniline was studied in buffer solution/acetonitrile mixture in different pHs. Our electrochemical data assert that the product of oxidation of 4-ethynylaniline is unstable in acidic and alkaline solution, and can be hydrolyzed in strong acidic (pH: 1–3) and alkaline (pH: 9–10) solutions. In continues, the electrochemical synthesis of 1,2-bis(4-ethynylphenyl) diazene was carried out by electrochemical oxidation of 4-ethynylaniline in aqueous HCl buffer and in a simple undivided cell, using carbon anode. The electrochemical reaction of 4-ethynylaniline (4-EA) in the presence of sodium azide in buffered solutions with the various pHs (buffer solution /acetonitrile (80/20 v/v)) was investigated for the first time. Our electrochemical data assert that the product of oxidation of 4-ethynylaniline enters the chemical reaction with azide ion. In continues, after the 1,3 dipolar cycloaddition, electrochemical oxidation, dimerization, and third step electrochemical oxidation a triazole ring was produced as the desired product in a simple undivided cell and using carbon anode. Electrochemical oxidation of 3 and 4 substituted catechols in the presence of 4-ethynylanilin as a nucleophile in acetonitrile/ sodium acetate 0.15M (30/70) solution has been carried out in detail with employing the cyclic voltammetry and controlled potential coulometry methods. The results show that the o-benzoquinones derived from these catechols participate in Michael type reaction with this nucleophile to form the corresponding new p-quinone imines.
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