10H-Pyrazino[2,3-b][1,4]benzotellurazine, a Novel Tellurium-Containing Heterocyclic System

Abstract

Condensation of 2,3-dichloropyrazine with 2-aminobenzenetellurole and 2-amino-5-methylbenzenetellurole, generated in situ by reduction of the corresponding ditellurides, resulted in the formation of novel 10H-pyrazino[2,3-b][1,4]benzotellurazine and its 7-methyl derivative. The products were purified via their well-crystallized 5,5-dibromo derivatives. X-ray crystallographic analysis of the title compound indicates that it has a pronounced V-shape and forms hydrogen-bonded dimers. Te, N-containing heterocycles have the potential of offering access to supramolecular assemblies.

[1,4]Ditellurino[2,3-b:5,6-b′]dipyrazine

“…The corresponding selenium congener remains unreported. The shape of the title compound shows structural similarity to those of 9,10-dichalcogenanthracenes containing tellurium and one other chalcogen atom in the central ring (Dereu et al, 1981;Meyers et al, 1988), as well as to the recently characterized 10H-pyrazino[2,3-b][1,4]benzotellurazine (Smith et al, 2020). All are V-shaped, but the extent to which the center ring is folded varies considerably.…”

“…(Smith et al, 1973), VEHVUZ (Meyers et al, 1988), VEHWEK (Meyers et al, 1988), and BAVJIR (Dereu et al, 1981), respectively. A further comparison was carried out with the sulfur analog of the title compound, WIBWEJ (Lynch et al, 1994), as well as with benzo[1,4]tellurazine derivatives HABJID (Junk et al, 1993), UGIHIEL (Smith et al, 2020) and BUTNOV (Myers et al, 2016). A comparison with other Te, Ncontaining heterocycles known to undergo supramolecular TeÁ Á ÁN bonding included 1,3-benzotellurazoles OLUQIX (Kremer et al, 2016), RUVWUC (Kremer et al, 2015), HALWID (Sanford et al, 2017) and 3,4-dicyano-1,2,5telluradiazole AREGEK01 (Semenov et al, 2012).…”

“…Not all Te, N-containing heterocycles form supramolecular wires or ribbons. Thus, 10H-pyrazino[2,3-b][1,4]benzotellurazine (Smith et al, 2020), 2H-1,4-benzo-tellurazin-3(4H)-one and 2,3-dihydro-1,5-benzotellurazepin-4(5H)-one (Myers et al, 2016) lack this data reports feature. The [1,4]dichalcogena[2,3-b:5,6-b 0 ]dipyrazines remain poorly explored and no examples containing heavy chalcogens were reported prior to this study.…”

“…The title compound and telluranthrene (' = 57.86 ) are nearly identical in this respect, while analogous compounds containing nitrogen as one apex heteroatom show much a less pronounced V shape. This is exemplified by dibenzo[b,e]tellurazine, with ' = 18.28 (Junk et al, 1993) and 10H-pyrazino[2,3-b][1,4]benzotellurazine, ' = 18.29 (Smith et al, 2020) for the central C 2 TeN moieties.…”

“…These fall between those of 2.767 (6) and 2.659 (6) A ˚reported for 3,4-dicyano-1,2,5-telluradiazole (Cozzolino et al, 2010) and those for benzo-1,3-tellurazoles, ranging from 2.985 A ˚for 2-(methylsulfanyl)-1,3-benzotellurazole (Ali et al, 2016) to 3.169 A ˚for 2-(2-furyl)-1,3-benzotellurazole (Kremer et al, 2016). In contrast, despite its structural similarity, 10Hpyrazino[2,3-b][1,4]benzotellurazine does not exhibit any supramolecular TeÁ Á ÁN bonding but forms hydrogen-bonded dimers instead (Smith et al, 2020).…”