Triazole derivatives R 0280 A Facile Entry for Synthesis of 3-Arylazo Derivatives of [1,2,4]Triazolo[4,3-a]benzimidazole and [1,2,4]Triazolo[3,4-b]quinazolin-5-one. -The synthesis of novel title arylazo derivatives (III) and (V) via reaction of 3-chloro-1,5-diarylformazans (II) with appropriate heterocyclic thiols and a possible reaction mechanism for their formation are reported. -(SHAWALI*, A. S.; SAYED, A. R.; J. Chem. Res. 2005, 5, 285-288; Dep. Chem., Fac. Sci., Cairo Univ., Giza 12613, Egypt; Eng.) -R. Staver 43-150