89879-95-8Relevant articles and documents
Cyclic Meso-ionic Compounds. Part 23. Novel Chemistry of 1,2,4-Thiadiazoles and Their Transformation into Meso-ionic 1,2,4-Thiadiazolium Derivatives
Newton, Christopher G.,Ollis, W. David,Wright, Derek E.
, p. 75 - 84 (2007/10/02)
Representatives of two new classes of meso-ionic heterocycles have been synthesised, the 1,2,4-thiadiazolium-3-olate (8) and the 1,2,4-thiadiazolium-3-tosylaminide (25).The reactions of 1,2,4-thiadiazoles and nucleophiles follow two general pathways: (i) reductive transformation to N-thiobenzoyl derivatives and (ii) elimination of elemental sulphur and the formation of N-benzoyl derivatives.A mechanistic rationale is proposed for the operation of pathways (i) and (ii).Earlier views on the oxidative formation of certain 1,2,4-thiadiazoles are corrected.A novel synthetic route to heterocycles containing sulphur-nitrogen bonds is described. 1,2,4-Thiadiazoles are formed by oxidation of N-thiobezoylureas and N-thiobenzoylguanidines by bis(4-methoxyphenyl) telluroxide.