Synthesis of triazenes by using aryl diazonium silica sulfates under mild conditions

• An efficient procedure for the synthesis of aryltriazenes is described.
• Temperature dependent NMR spectra were studied for 1-(2-nitrophenyl)-3,3-diethyltriazene.
• The rotational barrier energy was obtained 16.07 kcal mol−1 for 1-(2-nitrophenyl)-3,3-diethyltriazene.
• The rotational barrier energy of a number of triazenes was compared.

An efficient, fast and straightforward procedure for the synthesis of aryltriazenes is described in the present paper by using aryl diazonium silica sulfates and secondary amines. Using the present method, different kinds of aryl diazonium silica sulfates, containing electron withdrawing groups as well as electron donating groups, were rapidly converted to the corresponding of aryltriazenes in good yield and short reaction time. These reactions were carried out in water at room temperature under mild and heterogeneous conditions. Moreover, temperature dependent NMR spectra were studied for 1-(2-nitrophenyl)-3,3-diethyltriazene to determine the rotational barrier energy around N(2)–N(3) bond of this molecule. Simple and clean work-up, short reaction times and good yields were the advantages of this method.

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