Di­phenyl 3,6-bis(4-chloro­phenyl)-1,2-di­hydro-1,2,4,5-tetrazine-1,2-di­carboxyl­ate

The title compound, C₂₈H₁₈Cl₂N₄O₄, was prepared by the reaction of phenyl chloro­formate and 3,6-bis(4-chloro­phenyl)-1,4-di­hydro-1,2,4,5-tetrazine. The structural identity, confirmed by crystal structure determination, revealed a re-arrangement, resulting in formation of the 1,2-di­hydro­tetrazine derivative from the starting materials. The central tetrazine ring adopts a twist conformation.

3,6-Bis(p-chloro­phen­yl)-1,4-bis­(p-tolyl­sulfon­yl)-1,4-dihydro-1,2,4,5-tetra­zine

The title compound, C₂₈H₂₂Cl₂N₄O₄S₂, was prepared from triethyl­amine and N-(α,4-dichloro­benzyl­idene­amino)-p-toluene­sulfonamide and proved to be a 1,4-dihydro-s-tetra­zine derivative. In the mol­ecule, which possesses a crystallographically imposed inversion centre, the tetra­zine ring is essentially planar.