Synthesis and Spectroscopic Properties of New Azo Dyes Derived from 3-Ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole

Abstract

New 1,2,4-triazole colorants were obtained, in high yields, by coupling 3-ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole (1) with diazotized aniline derivatives 2, 4 and 6. The azo dyes prepared in this work may exist in three tautomeric forms. We found that the tautomerism is influenced mainly by the nature of substituent at the para position of the aniline coupling component. This tautomerisation was observed in the NMR spectra of the dyes. The dyes were characterized by IR, 1 H-NMR, 13 C-NMR and MS spectroscopic techniques.

Classifications, properties, recent synthesis and applications of azo dyes

“…New generations of azo dyes have been synthesized by different synthetic methods, [109,110,111,112]. In this part we have cited some syntheses of the azo dyes containing chemical groups hydrazone, chromene and derivatives of 2-aminothiophene and 2-aminothiazoles [70,113,114,115].…”

“…According to Al-Sheikh et al [114], the coupling reaction of 3-ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole (1) with benzene diazonium chloride 2 and then coupling of the diazonium salt with compound 1 in an aqueous solution of ethanol in the presence of a buffered solution of sodium acetate. This reaction yields 5-ethylthio-N 0 , 4-diphenyl-4H-1, 2, 4-triazole-3-carbohydrazonoyl (3B) with excellent yield.…”

A Novel Synthesis of 1‐Aryl‐6‐bromo‐3‐(5‐ethylthio‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐pyrazolo[4,3‐b]quinolin‐9(4H)‐ones via Thermal Cyclization of 4‐Azidopyrazoles

“…The required starting 2‐aryl‐hydrazononitriles 3a , 3b , 3c were prepared by coupling 3‐ethylthio‐5‐cyanomethyl‐4‐phenyl‐1,2,4‐triazole ( 1 ) with diazonium salts 2a , 2b , 2c in aqueous ethanol in the presence of sodium acetate‐buffered solution as previously reported from our laboratory (Scheme ).…”

Synthesis and antimicrobial activity of aryldiazenyl/arylhydrazono pyrazoles

“…Azo (-N=N-) and related hydrazo (=N-NH-) groups are essential pharmacophores for the synthesis of antimicrobial agents. 6,7 Furthermore, pyrazole derivatives are an interesting class of compounds showing a broad range of biological activities such as anticancer, 8 antimalarial, 9 antiviral, 10 and antimicrobial. 11 (ADPs) were carried out in two steps.…”