Dihydro‐ und Tetrahydroderivate des 3,6‐Dimethyl‐1,2,4,5‐tetrazins

Abstract

Abstract The scheme 1 shows those tetrahydro‐ and dihydroderivatives of the 3,6‐dimethyl‐1,2,4,5‐tetrazine (or s ‐tetrazine), 8 , which are theoretically possible without considering cis‐trans isomerism, together with the reaction pathways. We did not succeed in synthetizing the 3,6‐dihydroderivative, 7 , and could not isolate the 1,2‐dihydrocompound, 4 , the latter being probably easily convertible to the thermodynamically more stable 1,4‐dihydro‐ s ‐tetrazine, 5 , via their common conjugate base 4,5B . The 1,4‐dihydro‐ s ‐tetrazine, 5 , gives with 3,6‐dimethyl‐ s ‐tetrazine 8 , a charge transfer complex, 15 . The same compounds form in acidic or basic aquious solution stable radicals, 16B and 16S . The mode of formation of these radicals and the subsequent reactions are depicted in scheme 2.