1-Chloro-4-propoxythio­xanthone

In the title compound (systematic name: 1-chloro-4-propoxy-10-thia­anthracen-9-one), C₁₆H₁₃ClO₂S, the asymmetric unit contains two parallel molecules. In both molecules, the three rings in the thio­xanthone moiety are coplanar, the deviations being within the range ±0.086 (3) Å.

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

The central six-membered ring of the title compound, C₂₈H₂₄N₄O₄S₂, has a boat conformation, in which the N atoms bonded to sulfonyl groups deviate from the plane of the other four atoms by 0.389 (4) and 0.343 (4) Å.

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.

Ethyl 3,6-di­phenyl-1,4-di­hydro-1,2,4,5-tetrazine-1-carboxylate

The title compound, C₁₇H₁₆N₄O₂, was prepared from ethyl chloro­formate and 3,6-di­phenyl­di­hydro-1,2,4,5-tetrazine. The central six-membered ring has an asymmetric boat conformation.

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

The title compound, C₂₂H₂₂Cl₂N₄O₄, was prepared from prop­yl chloro­formate and 3,6-bis­(4-chloro­phen­yl)-1,2-dihydro-1,2,4,5-tetra­zine. The six-membered 1,2-dihydro-1,2,4,5-tetra­zine ring has a twist conformation.

Prop­yl 3,6-diphen­yl-1,4-dihydro-1,2,4,5-tetra­zine-1-carboxyl­ate

The title compound, C₁₈H₁₈N₄O₂, was prepared from prop­yl chloro­formate and 3,6-diphen­yl-1,2-dihydro-1,2,4,5-tetra­zine. The central six-membered ring has a boat conformation. In the crystal structure, mol­ecules are linked via N—H...N [N...N = 3.015 (4) Å] and C—H...O [C...O = 3.265 (6) Å] hydrogen bonds to form extended chains along [100].

3,6-Bis(4-chloro­phen­yl)-1-isobutyr­yl-1,4-dihydro-1,2,4,5-tetra­zine

The title compound, C₁₈H₁₆Cl₂N₄O, was prepared from isobutyric anhydride and 3,6-bis­(4-chloro­phen­yl)-1,2-dihydro-1,2,4,5-tetra­zine. The central six-membered ring has a boat conformation.

Diethyl 1,4-dihydro-1,2,4,5-tetra­zine-3,6-dicarboxyl­ate

The title compound, C₈H₁₂N₄O₄, was prepared from ethanol and 1,4-dihydro-1,2,4,5-tetra­zine-3,6-dicarboxylic acid. The central six-membered ring has a boat conformation.