Osotriazoles

The triazoles formed on oxidising arylosazones (commonly called osotriazoles) may also be named as triazolylalditols. 

Osotriazole aus 1-Xylose-, f-Rhammose- und d-Chinovose-phenylosazon, by E. Hardegger and H. El Khadem, Helv. Chim. Acta, 30 (1947) 900-904. 

In zahlreichen Arbeiten untersuchten El Khadem et al. i i.i32) unter anderem den EinfluB von Substituenten an den Phenylkernen der Osazone. Danach verlangsamen Substituenten in p-Stellung mit Elektronen-acceptorwirkung die Osotriazol-Bildung, wahrend Elektronendonatoren die Geschwindigkeit und die Ausbeute erhohen. 

The bishydrazones of the 1,2-diketones from inositols have also been converted into triazoles.222,223 The conversion of arylosazones into the corresponding osotriazoles requires the presence of an oxidant, and it is obvious that simple removal of aniline from the osazone, as suggested by the equation, is not involved. In addition to copper(II) sulfate, the reagent most commonly used, other oxidizing heavy-metal salts, such as ferric sulfate and chloride,224 and mercuric acetate,223 have been used, as well as halogens225 and nitro-sulfonates.226 The osazone acetates are converted into osotriazoles by nitrous acid,227 which decomposes the unacetylated osazones to the aldosuloses228 and the osazone formazans are cyclized with warm... 

The first 1,2,4-triazoles were prepd in 1885 by J.A. Bladin (Ber 18), who did considerable work in the investigation of this class of compd H. vonPechmann published a paper in 1888 in which he described the prepn of some derivatives of 1,2,3-triazoles and proposed naming them Osotriazones because they were prepd from osazone . This name, was changed in 1891 by vonPechmann to osotriazole . A. Andreocci also investigated triazoles, and in 1889 and 1894 published papers in which he called some of them Pyrrodiazoles . All of these compds are now called triazoles ... 

Methyl-4-Bromo-1,2,3-Triazole (N-Methyl-C-Bromo-Osotriazole). 

The 1,2,3-triazole system can be formally derived from pyrrole or indole by replacing two carbons by two nitrogen atoms. The resulting parent compounds may be classified in terms of the constitutional formulae (l)-(3). In the literature this ring system is still named u-triazole , in order to distinguish it from s-triazole . While (1) and (2) can be considered to depict heteroaromatic systems, (3) is a non-aromatic compound and is rarely found in the literature. In the older literature the term osotriazole belongs to derivatives of (2), particularly if these are derived from osazones. 

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