Synthesis of some new 1,2,4-triazoles starting from isonicotinic acid hydrazide and evaluation of their antimicrobial activities

Triazolothiadiazoles and triazolothiadiazines--biologically attractive scaffolds.

Hydrazonoyl halides: Useful building blocks for the synthesis of arylazoheterocycles

Synthesis of some new azo dyes derived from 4-hydroxy coumarin and spectrometric determination of their acidic dissociation constants

Mercapto-substituted 1,2,4-triazoles are very interesting compounds as they play an important role in chemopreventive and chemotherapeutic effects on cancer. In recent decades, literature has been enriched with sulfur- and nitrogen-containing heterocycles which are used as a basic nucleus of different heterocyclic compounds with various biological applications in medicine and also occupy a huge part of natural products. Therefore, we shed, herein, more light on the synthesis of this interesting class and its application as a biologically active moiety. They might also be suitable as antiviral and anti-infective drugs.

Chemistry and Biological Activities of 1,2,4-Triazolethiones—Antiviral and Anti-Infective Drugs

7-Arylhydrazono[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines 4 were synthesized from the reactions of 4-amino-5-phenyl-4H-[1,2,4]triazole-3-thiol 2 and 2-(2-naphthyl)-2-oxoethanehydrazonoyl bromides 1 and their acid dissociation constants pK and pK*, in the ground and excited states, respectively, were determined. Both pK and pK* constants were correlated by Hammett equation. The pK and the spectral data presented indicate that the title compounds exist predominantly in the hydrazone tautomeric form.

Ibrahim F. Zeid

Papers

Synthesis, Acidity Constants and Tautomeric Structure of 7-Arylhydrazono[1,2,4]Triazolo[3,4-b][1,3,4]thiadiazines in Ground and Excited States