Sydnone imine salts

Oxatriazolium-5-aminides (9) are structurally related to sydnon-imines (3). As with sydnonimines, the 5-imine derivatives are stable only as salts or in their N-acylated forms. 3-Cyclohexyl-1,2,3,4-oxatriazole-5-imine hydrochloride was first synthesized by Finnegan and Henry in 1965 [55]. The biological activity was reported by Masuda et al. in 1971 [56]. Oxatriazole-5-imines (9) have been reported to be an important class of NO donors and potent antiplatelet, fibrinolytic, thrombolytic, and bronchiectatic agents [57]. However, an extensive investigation of the NO-releasing and other biologi-... 

Six articles cover general aspects of heterocyclic chemistry 1,3-dipolar cycloreversions, syntheses with arylnitrenes and a-metallated isocyanides, and photo-oxygenation of nitrogen heterocycles,while others deal with more specialized subjects, i.e. preparation and use of halogeno-lactones, aspects of the chemistry of furan, 1-hydroxy-indoles, ring-opening of azoles by the action of amines, " the use of 2-chlorobenzoxazolium (1) and other heterocyclic onium salts for dehydration and condensation reactions," the synthesis of monosub-stituted tetrathiafulvalenes (2), cycloadditions of azoles containing three heteroatoms,sydnone imines (3), the conversion of acyl-benzofuroxans into nitro-indazoles (cf. p. 199), and advances in the chemistry of pyrrolizidine " and indolizine." ... 

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