Synthesis, Characterization and absorption properties of some novel heterocyclic tetrakisazo dyes

Abstract

Objective: The aim of the work was to designed and synthesized novel heterocyclic tetrakisazo dyes.Methods: 2,2'[(4,4'-dihydrazonebiphenyl)]-bis(3-iminobuthyronitrile) (1) were synthesized by diazotization of benzidine using hydrochloric acid in water. Compounds (1) reacted with hydrazine hydrate to afford the corresponding 4,4'-bis [3-methyl-5-amino-1-H-pyrazol-4-ylazo]biphenyl (2). Seven novel hetaryltetrakisazobenzidine Derivatives 3(a-g) were achieved by diazotization of 4,4'-bis [3-methyl-5-amino-1-H-pyrazol-4-ylazo]biphenyl and coupling with various coupling components.Results: The obtained hetaryltetrakisazo dyes 3(a-g) were characterized based on FT-IR, 1H-NMR, and mass spectroscopic techniques as well as elemental analysis. The solvatochromic behavior of these dyes in various solvents was examined. Acid-base effects on the visible absorption maxima of the dyes were also reported.Conclusion: Synthesis and characterization of seven of these nine novel compounds synthesized, which are hetaryltetrakisazo dyes 3(a-g). © 2014,International Journal of Pharmacy and Pharmaceutical Sciences All Rights Reserved