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

Abstract

A simple synthetic strategy is described for synthesis of hitherto unreported 3-arylazo derivatives of both [1,2,4]triazolo[4,3-a]benzimidazole and [1,2,4]triazolo[3,4-b]quinazolin-5-one 6 and 7, respectively. This strategy utilises reactions of 3-chloro-1,5-diarylformazans 1 with 2-mercaptobenzimidazole 2 and 2,3-dihydro-2-thioxoquina-zolin-4(1H)-one 4 or their 2-methylthio derivatives 3 and 5, respectively. A plausible reaction mechanism is suggested for the formation of the isolated products 6 and 7.

Functionalized formazans: A review on recent progress in their pharmacological activities

“…In contrast to these comprehensive literature reports on the chemistry of formazans, there has been no survey of their biological activities hitherto although they have been found to possess wide spectrum of biological activities such as antiviral, antimicrobial, anti-inflammatory, antifungal, anticancer, anti HIV. Based on these findings and in continuation of our studies of the chemistry of both 3-chloro-1, 5-diarylformazans 2 [17–21] and the related hydrazonoyl halides 3 [22–35] ( Chart 1 ), it was thought necessary to present this review. Our objective is to shed light on the recent developments in biological activities of various functionalized formazans 1 ( Chart 1 ).…”

Synthesis of a new triheterocycle. Bis-pyrazolo[1,5-a][4',3'-e]pyrimidine

“…In continuation of our studies dealing with the utility of hydrazonoyl halides for synthesis of various heterocyclic ring systems, [1][2][3][4][5][6][7][8][9][10][11] we wish to report herein a new facile synthesis of bispyrazolo [1,5-a][4',3'-e]pyrimidine ring system and its various functionalized derivatives that have not been reported hitherto. The earlier methods reported for synthesis of such ring system are multisteps.…”