1,2,5-Oxadiazoles

Synthesis of 3-methyl-4-(5-R-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazoles

“…1 Recently, furazans containing various het erocyclic substituents have attracted attention as AKT ki nase inhibitors, 2 antagonists of neurokinin 3 receptors (NK 3), 3 antiarrhythmic agents, 4 etc. Earlier, we have published data on the synthesis of 1,2,5 oxadiazole (fura zan) derivatives with 1,2,4 oxadiazole 5 and tetrazole sub stituents 6 at the C(4) atom of the furazan ring.…”

“…Experimental1 H NMR spectra were recorded on Bruker WM 250 and Bruker AM 300 instruments (250 and 300 MHz, respectively) in DMSO d6 . Chemical shifts are expressed in terms of the δ scale and referenced to SiMe 4 .…”

Lewis acid-catalyzed Wolff cyclocondensation in the synthesis of (1H-1,2,3-triazolyl)furoxans

“…[5][6][7][8][9][10][11][12] On the other hand furoxan derivatives reveal a wide spectrum of pharmacological activity owing to their ability to release NO under physiological conditions. [13][14][15][16][17][18][19] Our last developments resulted in new, effective one-pot approaches for the synthesis of a series of hybrid heterocyclic systems incorporating furoxan ring connected with various pharmacophoric and/or energy rich poly-nitrogen (nitrogen-oxygen) heterocycles (isomeric 1,2,3-and 1,2,4-triazoles, 1,2,4-and 1,3,4-oxadiazoles, tetrazole, pyridines, tetrahydroisoquinoline, indenopyridine, etc.). [20][21][22][23][24][25][26][27][28] Among synthesized compounds (1,2,3-triazol-1-yl)furoxan derivatives 1 attract special attention due to a wide variety of their pharmacological activity.…”

An exploration of the mechanisms for the formation of 3,4-bis(4-aminofurazan-3-yl)-furoxan by density functional theory

“…Among these methods, dimerization of nitrile oxides is the most straightforward and most commonly used one. Nitrile oxides are widely used as participants in 1,3-dipolar cycloadditions leading to fivemembered heterocycles, and nitrile oxides (especially for lower aliphatic and acyl nitrile oxides) can dimerize easily to form furoxans [1]. Three methods have been used for the generation of the nitrile oxides: isocyanate-mediated dehydration of nitromethylmannose derivatives, treatment of aldoxime with aqueous hypochlorite, and base-induced dehydrochlorination of hydroximoyl chloride [15,16].…”

“…In recent years, derivatives of 1,2,5-oxadiazole-2-oxides, commonly known as furoxans (Scheme 1), have attracted considerable attention due to their wide range of applications in organic chemistry and pharmaceuticals as starting materials and intermediate compounds for the synthesis of numerous heterocycles [1,2]. On the one hand, furoxan derivatives possess an exceptional combination of chemical and physical characteristics: easy ring opening [3], tautomerism [4], transformations in reactions with both nucleophiles and electrophiles.…”