Rational synthesis and characterization of medicinal phenyl diazenyl-3-hydroxy-1h-inden-1-one azo derivatives and their metal complexes

Abstract

The emergence of resistance to the major classes of antibacterial drug is recognized as serious health concern. So the development of new and more effective antimicrobial agents are necessary for human health. In this study a new series of azo based 1,3-indandion derivatives (4-MHPD, 2-BrHPD, 3-BrHPD 2-IHPD and 4-IHPD) was synthesized by reacting 1,3-indandion with various anilines (4- methyl aniline, 2-bromo aniline, 2-bromo aniline 2-isopropyl aniline and 4-isopropyl aniline) by diazotization, and metal complexes (Cu2+, Zn2+, Ni2+ and Mn2+) in mild, efficient, and convenient method with good yields in less time. All the newly synthesized compounds were characterized by IR, NMR (1H, &13C), UV/VIS and mass spectrometry. The appearance of -N=N- peak at 1400–1500 cm−1 with disappearance of NH2 peak at 3500 cm−1 in FTIR spectra and chemical shift at 11.00–13.00 ppm for -OH protons confirmed the synthesis of new azo derivatives. The appearance of C-OH sharp peak at 180–190 ppm and appearance of molecular ion peaks at 264 m/z, 329 m/z and 292 m/z and respectively further gives strong indication for the synthesis of proposed azo derivatives. Synthesized compounds were also screened for their antioxidant, antibacterial, antifungal, chymotrypsin and tyrosinase inhibition activities. Result have shown that among synthesized compounds, 2-IHPD, 2-BrHPD, 4-MHPD and their metal complexes with Cu2+ and Zn2+ have shown greater inhibitions against standard drugs. Furthermore structure activity and metal complexes versus ligands activity relationship were also explored in this study which revealed that presence of electron donating, halogen group and presence of transition metals enhanced the biological activities of tested compounds.