Synthesis and structural characterization of some novel methoxyamino derivatives with acid-base and redox behavior

• Published in: Journal of molecular structure 2018-12, Vol.1173, p.291-299
• Main Authors: Bem, M., Baratoiu, R., Radutiu, C., Lete, C., Mocanu, S., Ionita, G., Lupu, S., Caproiu, M.T., Madalan, A.M., Patrascu, B., Zarafu, I., Ionita, P.
• Format: Article
• Language: English
• Subjects: Acid-base; Free radical; Redox; Structural characterization; Synthesis
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2018.06.114

A series of novel derivatives of 3,5-dinitro-4-methoxyamino-benzoic acid were synthesized and fully characterized. Synthesis were performed by simple coupling reactions of the starting material with benzylamine, n-butylamine, 4-amino-antipyrine, benzocaine, 3,4-dimethyl-5-amino-isoxazole, 3,4-dimethoxyphenyl-2-ethylamine; besides, the corresponding methyl ester was also synthesized. The structural characterization of the new compounds was made by elemental analysis, IR, 1H and 13C NMR, UV–Vis, ESR, cyclic voltammetry, and single crystal X-ray diffraction (where appropriate). All compounds exhibits reversible acid-base behavior accompanied by colour change (yellow in acid media and blue at basic pH). Cyclic voltammetry showed an irreversible oxidation peak, however by chemical oxidation, these compounds generates persistent free radicals, evidenced also by ESR. Hydrophobicity and total antioxidant capacity of the compounds were also evaluated. UV–Vis spectra for compound 1 (in red) and for its corresponding anion (in blue). [Display omitted] •New methoxyamino-derivatives synthesized and fully characterized.•acid-base (colour changing) and redox behavior (persistent free radicals).•Experimental and calculated hydrophobicity and total antioxidant capacity evaluated.