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Journal articles on the topic '4-b]-pyrazine'

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Published: 4 June 2021

Last updated: 5 February 2022

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1

Wang, Cui-ping, Jing-bo Yan, Hai-Jun Chi, Yan Dong, and Zhi-qiang Zhang. "3-(4-Methoxyphenyl)pyrido[2,3-b]pyrazine." Acta Crystallographica Section E Structure Reports Online 66, no. 10 (September 30, 2010): o2650. http://dx.doi.org/10.1107/s1600536810037943.

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2

Starchenkov, I. B., and V. G. Andrianov. "Chemistry of furazano[3,4-b]pyrazine. 4. 5,6-Dichlorofurazano[3,4-b]pyrazine in cyclization reactions." Chemistry of Heterocyclic Compounds 33, no. 11 (November 1997): 1352–54. http://dx.doi.org/10.1007/bf02320341.

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3

Koch, Pierre, Dieter Schollmeyer, and Stefan Laufer. "2-(4-Fluorophenyl)-3-(4-pyridyl)pyrido[2,3-b]pyrazine." Acta Crystallographica Section E Structure Reports Online 65, no. 10 (September 26, 2009): o2512. http://dx.doi.org/10.1107/s1600536809037295.

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4

Koch, Pierre, Dieter Schollmeyer, and Stefan Laufer. "3-(4-Fluorophenyl)-2-(4-pyridyl)pyrido[2,3-b]pyrazine." Acta Crystallographica Section E Structure Reports Online 65, no. 10 (September 26, 2009): o2546. http://dx.doi.org/10.1107/s1600536809037970.

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5

STARCHENKOV, I. B., and V. G. ANDRIANOV. "ChemInform Abstract: Chemistry of Furazano[3,4-b]pyrazine. Part 4. 5,6-Dichlorofurazano[3,4-b]pyrazine in Cyclization Reactions." ChemInform 29, no. 20 (June 22, 2010): no. http://dx.doi.org/10.1002/chin.199820198.

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6

Baron, Aurelie, Graham Sandford, Rachel Slater, Dmitry S. Yufit, Judith A. K. Howard, and Antonio Vong. "Polyfunctional Tetrahydropyrido[2,3-b]pyrazine Scaffolds from 4-Phenylsulfonyl Tetrafluoropyridine." Journal of Organic Chemistry 70, no. 23 (November 2005): 9377–81. http://dx.doi.org/10.1021/jo051453v.

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7

Wang, Yanling, Qiang Peng, Ping He, Zaifang Li, Ying Liang, and Benlin Li. "Theoretical Design Study on Photophysical Properties of Light-emitting Pyrido[3,4-b]pyrazine-based Oligomers." Australian Journal of Chemistry 65, no. 2 (2012): 169. http://dx.doi.org/10.1071/ch11427.

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The electronic structures, charge injection and transport, and absorption and emission properties of four series of dimethylpyrido[3,4-b]pyrazine-based oligomers (5-(5,5-dimethyl-5H-dibenzo[b,d]silol-3-yl)-2,3-dimethylpyrido[3,4-b]pyrazine)n (SPP)n, (5-(dibenzo[b,d]thiophen-3-yl)-2,3-dimethylpyrido[3,4-b]pyrazine)n (TPP)n, (5-(9,9-dimethyl-9H-fluoren-2-yl)-2,3-dimethylpyrido[3,4-b]pyrazine)n (FPP)n, (2-(2,3-dimethylpyrido[3,4-b]pyrazin-5-yl)-9-methyl-9H-carbazole)n (PPC)n were investigated by the density functional theory approach. The ground-state geometries of (SPP)n, (TPP)n, (FPP)n and (PPC)n (n = 1–4) were optimized at the B3LYP/6–31G(d) level. The energies of the HOMO, LUMO and HOMO–LUMO energy gaps of (SPP)n, (TPP)n, (FPP)n and (PPC)n (n = 1–4) were obtained by a linear extrapolation method. Further, calculations of ionization potential, electronic affinity and reorganization energy were used to evaluate charge injection and transport abilities. For (SPP)n, (TPP)n, (FPP)n and (PPC)n (n = 1–4), the time-dependent density functional theory (TDDFT) calculation results revealed that the absorption peaks can be characterized as π–π* transitions and are coupled with the location of electron density distribution change in different repeat units. All the primary theoretical investigations are intended to establish structure–property relationships, which can provide guidance in designing and preparing novel efficient organic light-emitting materials with a high performance.

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8

Starchenkov, I. B., and V. G. Andrianov. "4H,8H-bis(1,2,5-oxadiazolo)[3,4-b:3',4'-e]Pyrazine." Chemistry of Heterocyclic Compounds 32, no. 5 (May 1996): 618. http://dx.doi.org/10.1007/bf01164797.

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9

Snyder, Christopher J., Lucille A. Wells, David E. Chavez, Gregory H. Imler, and Damon A. Parrish. "Polycyclic N-oxides: high performing, low sensitivity energetic materials." Chemical Communications 55, no. 17 (2019): 2461–64. http://dx.doi.org/10.1039/c8cc09653h.

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10

Sheremetev, Aleksei B., and Igor L. Yudin. "Synthesis of unsubstituted 4H,8H-bisfurazano[3,4-b:3′,4′-e]pyrazine." Mendeleev Communications 6, no. 6 (January 1996): 247–48. http://dx.doi.org/10.1070/mc1996v006n06abeh000746.

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11

Assoumatine, Tokouré, and Helen Stoeckli-Evans. "Silver(I) nitrate two-dimensional coordination polymers of two new pyrazinethiophane ligands: 5,7-dihydro-1H,3H-dithieno[3,4-b:3′,4′-e]pyrazine and 3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine." Acta Crystallographica Section E Crystallographic Communications 76, no. 4 (March 13, 2020): 539–46. http://dx.doi.org/10.1107/s205698902000362x.

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The two new pyrazineophanes, 5,7-dihydro-1H,3H-dithieno[3,4-b:3′,4′-e]pyrazine, C8H8N2S2, L1, and 3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine, C12H16N2S4, L2, both crystallize with half a molecule in the asymmetric unit; the whole molecules are generated by inversion symmetry. The molecule of L1, which is planar (r.m.s. deviation = 0.008 Å), consists of two sulfur atoms linked by a rigid tetra-2,3,5,6-methylenepyrazine unit, forming planar five-membered rings. The molecule of L2 is step-shaped and consists of two S–CH2–CH2–S chains linked by the central rigid tetra-2,3,5,6-methylenepyrazine unit, forming eight-membered rings that have twist-boat-chair configurations. In the crystals of both compounds, there are no significant intermolecular interactions present. The reaction of L1 with silver nitrate leads to the formation of a two-dimensional coordination polymer, poly[(μ-5,7-dihydro-1H,3H-dithieno[3,4-b;3′,4′-e]pyrazine-κ2 S:S′)(μ-nitrato-κ2 O:O′)silver(I)], [Ag(NO3)(C8H8N2S2)] n , (I), with the nitrato anion bridging two equivalent silver atoms. The central pyrazine ring is situated about an inversion center and the silver atom lies on a twofold rotation axis that bisects the nitrato anion. The silver atom has a fourfold AgO2S2 coordination sphere with a distorted shape. The reaction of L2 with silver nitrate also leads to the formation of a two-dimensional coordination polymer, poly[[μ33,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b;6′,7′-e]pyrazine-κ3 S:S′:S′′](nitrato-κO)silver(I)], [Ag(NO3)(C12H16N2S4)] n , (II), with the nitrate anion coordinating in a monodentate manner to the silver atom. The silver atom has a fourfold AgOS3 coordination sphere with a distorted shape. In the crystals of both complexes, the networks are linked by C—H...O hydrogen bonds, forming supramolecular frameworks. There are additional C—H...S contacts present in the supramolecular framework of II.

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12

Gobala Krishnan P, Gnanaprakash K, and Chandrasekhar KB. "Design, synthesis, characterization and antitubercular activity of some nov-el 2, 4-disubstituted thiazole derivatives." International Journal of Research in Pharmaceutical Sciences 10, no. 2 (April 23, 2019): 1504–9. http://dx.doi.org/10.26452/ijrps.v10i2.729.

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Literature reviews reveal that thiazole and pyrazine carboxamide derivatives exhibit anticonvulsant, antimicrobial, anticancer and anti-tubercular activities due to the presence of –S-C=N- and-CO–NH- moiety. A series of thiazolyl pyrazine carboxamide derivatives (5a-j) were synthesized by condensation reaction between 2-amino, 4-substituted phenyl 2-amino thiazole and pyrazine 2-carboxylic acid. These synthesized thiazole derivatives (5a-j) were evaluated for their inhibitory activity against Mycobacterium tuberculosis (Mtb), H37Rv using microplate Alamar Blue assay (MABA). The compound, 5c and 5h showed high anti-mycobacterial activity with MIC value of 6.25 µg/ml, and the compound 5g also exhibited anti-mycobacterial activity with MIC value of 12.50 µg/ml. Molecular docking studies of these synthesized molecules with b-Ketoacyl-ACP Synthase (KasA) protein of Mycobacterium tuberculosis (Mtb) have been carried out to understand the mechanism of anti-mycobacterial action.

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13

Dagley, IJ, and JL Flippenanderson. "Synthesis of Cyclic Nitramines From Products of the Cyclocondensation Reaction of Guanidine With 2,3,5,6-Tetrahydroxypiperazine-1,4-dicarbaldehyde." Australian Journal of Chemistry 47, no. 11 (1994): 2033. http://dx.doi.org/10.1071/ch9942033.

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The reaction of 2,3,5,6-tetrahydroxypiperazine-1,4-dicarbaldehyde (1) with guanidine hydrochloride in hydrochloric acid can be controlled to give 2,6-diiminododecahydrodiimidazo[4,5-b:4′,5′-e] pyrazine (2a) or the cis isomer of 4,5-diamino-2-iminoimidazolidine (4). Compound (4) reacts with formaldehyde, or formic acid followed by reduction, to give 2-iminooctahydroimidazo[4,5-d] imidazole (7). Treatment of (2a) or (7) with nitric acid gives dinitro derivatives that were isolated as nitric acid salts of the cyclic guanidines. Reaction of the dinitro derivatives with nitric acid/acetic anhydride in the presence of chloride ion gives 4,8-dinitro-2,6-bis( nitroimino ) dodecahydrodiimidazo -[4,5-b:4′,5′-e] pyrazine (3a) and 1,3-dinitro-5-( nitroimino ) octahydroimidazo [4,5-d] imidazole (9). The reaction of (7) with nitric acid/ trifluoroacetic anhydride was controlled to give either the tetranitro or a dinitro bis ( trifluoroacetyl ) derivative of the corresponding bicyclic urea.

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14

Moreno, J. M., J. Suarez-Varela, E. Colacio, J. C. Avila-Rosón, M. A. Hidalgo, and D. Martin-Ramos. "A two-dimensional copper(I) polymer containing both molecular rod and anionic bridges: synthesis and crystal structure of (µ-chloro)-(µ-pyrazine)copper(I)." Canadian Journal of Chemistry 73, no. 10 (October 1, 1995): 1591–95. http://dx.doi.org/10.1139/v95-197.

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The crystal structure of bright-red crystals of the bidimensional polynuclear diamagnetic (µ-chloro)(µ-pyrazine)copper(I) complex has been analyzed from X-ray diffraction data. The structure was solved by the heavy-atom method. Full-matrix least-squares refinement based on 673 reflections with F > 4σ(F) converged to a final R = 0.043 and Rw = 0.048. Crystals of this complex are monoclinic, space group P2/c, a = 3.814(1), b = 6.356(1) and c = 11.497(5) Å; β = 96.04(2)°, Z = 2. The structure consists of planes of copper(I) atoms linked by pyrazine and Cl− bridges, each Cu(I) being in a distorted tetrahedral environment formed by two chloride ions and two nitrogen atoms belonging to two pyrazine molecules, with bond distances of Cu—Cl = 2.349(1) and Cu—N = 2.038(4) Å. Vibrational and electronic spectroscopy of the title compound is also reported. Keywords: two-dimensional copper(I)–pyrazine complexes.

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15

STARCHENKOV, I. B., and V. G. ANDRIANOV. "ChemInform Abstract: 4H,8H-Bis(1,2,5-oxadiazolo)(3,4-b:3′,4′-e)pyrazine." ChemInform 27, no. 45 (August 4, 2010): no. http://dx.doi.org/10.1002/chin.199645186.

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16

Zhao, Guozheng, and Ming Lu. "Comparative theoretical studies of energetic dodecahydrodiimidazo[4,5-b:4′,5′-e]pyrazine derivatives." Computational and Theoretical Chemistry 1007 (March 2013): 57–62. http://dx.doi.org/10.1016/j.comptc.2012.12.009.

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17

Bock, Hans, Holger Schödel, and Thorsten Vaupel. "Wechselwirkungen in Kristallen, 112 [1]. Tetra(2-pyridyl)pyrazin - ein vielseitiger Ligand für Lewis-Säuren: Halb- und doppelschalige Komplexe von Kupfer(II)- und Nickel(II)-Salzen / Interactions in Crystals, 112 [1]. Tetra(2-pyridyl)pyrazine - a Versatile Ligand for Lewis Acids: Semi- and Doubly-Encapsulated Complexes of Copper(II) and Nickel(II) Salts." Zeitschrift für Naturforschung B 52, no. 4 (April 1, 1997): 515–23. http://dx.doi.org/10.1515/znb-1997-0413.

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Preceding cyclovoltammetric measurements of tetra(2-pyridyl)pyrazine (TPP) in aprotic THF solution and the lowering of the reduction potential on Li+[B(C6H5)4 ] addition, the crystallization of diprotonated [TPPH2++][B(CAH5)4-]2 and of [2,4,6-tris(2-pyridyl)-1,3,5- triazine(Li+)][B(C6H5)4-] have stimulated the preparation and structural characterization of the following (TPP)1,2 copper(II) and (TPP)2 nickel(II) salts: (1) Green TTP-copper(II)- dichlorideacetonitrile with Cu2+ fivefold coordinated by three N contacts to one TPP ligand and by two Cl anions, (2) green di(TPP)-copper(II)-di(perchlorate)·2 acetonitrile with fully encapsulated Cu2+ coordinated to six N centers of two TPP ligands, and (3) the analogous nickel(II) complex, brown di(TPP)-nickel(II)-bis-(tetrafluoroborat)·3 water-methanol. Both complexes [(TPP)Me2+(TPP)](X-)2 with the Me2+ dications in the cavity provided by two twisted TPP ligands are reported for the first time. The discussion of the crystal structures is based on an extensive search in the Cambridge Structural Database, which confirms the distortion mode around the penta-coordinated Cu2+ center, and a more strongly distorted octahedron at the Cu2+ center relative to that at the six-coordinate Ni2+ center as well as shorter contacts Me2+ ··· N to the pyrazine N centers than to the pyridine N centers. The comparison of the monodentate terpyridyl ligand with the bidentate tetra(2-pyridyl)pyrazine suggests the preparation of Me+n-bridged polymer chains terminated by terpyridyl complexation.

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18

SHEREMETEV, A. B., and I. L. YUDIN. "ChemInform Abstract: Synthesis of Unsubstituted 4H,8H-Bisfurazano(3,4-b:3′,4′-e)pyrazine." ChemInform 28, no. 15 (August 4, 2010): no. http://dx.doi.org/10.1002/chin.199715166.

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19

Kanno, Manabu, Yuta Ito, Noriyuki Shimakura, Shiro Koseki, Hirohiko Kono, and Yuichi Fujimura. "Ab initio quantum dynamical analysis of ultrafast nonradiative transitions via conical intersections in pyrazine." Physical Chemistry Chemical Physics 17, no. 3 (2015): 2012–14. http://dx.doi.org/10.1039/c4cp04807e.

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Ab initio quantum dynamical calculations reveal the contributions of the optically dark S₁ (¹B_3u), S₃ (¹A_u), and S₄ (¹B_2g) states to ultrafast nonradiative transition from the optically bright S₂ (¹B_2u) state in pyrazine and suggest a much faster transition rate than previously believed.

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20

Otieno, Tom, Steven J. Rettig, Robert C. Thompson, and James Trotter. "Pyrazine and 2,5-dimethylpyrazine complexes of copper(I) trifluoromethanesulfonate. The crystal and molecular structure of poly-μ-2,5-dimethylpyrazine-(2,5-dimethylpyrazine)-(trifluoromethanesulfonato-O)copper(I)." Canadian Journal of Chemistry 68, no. 10 (October 1, 1990): 1901–7. http://dx.doi.org/10.1139/v90-294.

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The complexes CuL2(CF3SO3) where L is pyrazine and 2,5-dimethylpyrazine have been prepared by the reaction of copper(I) triflate with the neutral ligand in methanol. Single crystal X-ray diffraction studies on the 2,5-Me2pyz complex are reported. Crystals of the compound are triclinic, a = 9.424(4), b = 12.103(4), c = 9.113(4) Å, α = 110.97(3), β = 117.20(3), γ = 80.26(3)°, Z = 2, space group [Formula: see text]. The structure was solved by heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.039 for 3326 reflections with I ≥ 3σ(1). The structure is similar to that of the pyz analogue involving chains of copper ions linked by bridging 2,5-Me2pyz ligands and monodenate triflate and terminal 2,5-Me2pyz ligands completing a distorted tetrahedral CuN3O chromophore. Mono-pyrazine and -2,5-dimethylpyrazine complexes of the type CuL(CF3SO3) were obtained by thermolysis of the corresponding bis-ligand complexes. These compounds are assigned a polymeric structure involving bridging neutral ligands and monodenate triflate groups on the basis of infrared spectroscopy studies. Electronic spectroscopy and differential scanning calorimetry studies are also reported. Keywords: pyrazine and 2,5-dimethylpyrazine complexes, copper(I) triflate, crystal structure.

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21

Bandaru, Siva Sankar Murthy, Anant Ramakant Kapdi, and Carola Schulzke. "Crystal structure of 4-(pyrazin-2-yl)morpholine." Acta Crystallographica Section E Crystallographic Communications 74, no. 2 (January 12, 2018): 137–40. http://dx.doi.org/10.1107/s2056989018000312.

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The molecular structure of the title compound, C8H11N3O, is nearly planar despite the chair conformation of the morpholine moiety. In the crystal, the molecules form sheets parallel to the b axis, which are supported by non-classical hydrogen-bonding interactions between C—H functionalities and the O atom of morpholine and the 4-N atom of pyrazine, respectively. The title compound crystallizes in the monoclinic space group P21/c with four molecules in the unit cell.

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22

Bobrov, A. V., B. B. Averkiev, S. G. Zlotin, and M. Yu Antipin. "ChemInform Abstract: Unusual Scission of 3,7-Dichlorobisisothiazolo[4,5-b:4′,5′-e]pyrazine by Nucleophiles." ChemInform 33, no. 15 (May 22, 2010): no. http://dx.doi.org/10.1002/chin.200215041.

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23

Döring, Cindy, Julian F. D. Lueck, and Peter G. Jones. "Structures of the adducts urea:pyrazine (1:1), thiourea:pyrazine (2:1) and thiourea:piperazine (2:1)." Zeitschrift für Naturforschung B 72, no. 6 (May 24, 2017): 441–45. http://dx.doi.org/10.1515/znb-2017-0045.

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AbstractThe adducts urea:pyrazine (1:1) (1), thiourea:pyrazine (2:1) (2), and thiourea:piperazine (2:1) (3) were prepared and their structures determined. Adduct 1 forms a layer structure, in which urea chains of graph set C(4)[${\rm{R}}_{\rm{2}}^{\rm{1}}$(6)] run parallel to the b axis and are crosslinked by N–H···N hydrogen bonding to the pyrazine residues. Adduct 2 is a variant of the well-known ${\rm{R}}_{\rm{2}}^{\rm{2}}$(8) ribbon substructure for urea/thiourea adducts, with the pyrazine molecules attached to the remaining thiourea NH groups via bifurcated hydrogen bonds (N–H···)2S; the more distant end of the pyrazine molecules is crosslinked to another symmetry-equivalent but perpendicular ribbon system, thus creating a three-dimensional packing. The packing of adduct 3 involves thiourea layers parallel to the ab plane; the piperazine molecules occupy the regions between these layers and are linked to the thiourea molecules by two hydrogen bonds (one as donor, one as acceptor) at each piperazine nitrogen atom.

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24

Enakieva, Yuliya Yu, Yuliya G. Gorbunova, Aslan Yu Tsivadze, Christine Stern, and Roger Guilard. "Ruthenium(II) meso-tetra-(benzo-15-crown-5)-porphyrinates: synthesis and spectroscopic investigation." Journal of Porphyrins and Phthalocyanines 11, no. 12 (December 2007): 883–90. http://dx.doi.org/10.1142/s1088424607001004.

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The synthesis of novel ruthenium(II) meso-tetra-(benzo-15-crown-5)-porphyrinates, meso-[( B 15 C 5)4 Por ] Ru ( CO )( MeOH ) (1) and meso-[( B 15 C 5)4 Por ] Ru ( L )2 (2)-(4) (meso-[( B 15 C 5)4 Por ]2-= 5,10,15,20-tetrakis-(benzo-15-crown-5)-porphyrinato-dianion; L = pyridine (py), pyrazine (pyz), 4,4′-bipyridyl (4,4′-bpy)), where CO and MeOH , or two N -donor ligands are axially coordinated to the central metal, are reported. The metalation of the free ligand performed by the reaction of Ru 3( CO )12 with meso-[( B 15 C 5)4 Por ] H 2 in 1,2,4-trichlorobenzene (TCB, bp = 215°C), gives (1) in a high yield. The synthesis of (2)-(4) involves the decarbonylation of (1) with trimethylamine N -oxide (( CH 3)3 NO ) in the presence of an excess of the N -donor ligand. The coordination of the axially bonded ligands is evidenced by different spectroscopic data.

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25

Battistini, Maurizio, Emanuela Erba, and Donato Pocar. "v-Triazolines; 33.1Synthesis of 3-Aminoquinoxaline 1-Oxides and 2-Aminopyrido[3,4-b]-pyrazine 4-Oxides." Synthesis 1992, no. 12 (1992): 1206–8. http://dx.doi.org/10.1055/s-1992-26335.

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26

TSELINSKII, I. V., S. F. MEL'NIKOVA, T. V. ROMANOVA, S. V. PIROGOV, G. KH KHISAMUTDINOV, T. A. MRATKHUZINA, V. L. KOROLEV, I. Z. KONDYUKOV, I. SH ABDRAKHMANOV, and S. P. SMIRNOV. "ChemInform Abstract: 4H,8H-Bis-(1,2,5-oxadiazolo)[3,4-b:3′,4′-e]pyrazine and Some Derivatives." ChemInform 29, no. 34 (June 20, 2010): no. http://dx.doi.org/10.1002/chin.199834178.

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27

SAVELLI, F., A. BOIDO, and G. DAMONTE. "ChemInform Abstract: Heterotricyclic Systems. Part 4. Synthesis of 1H-Pyrazino(1,2-a)pyrido( 2,3-e)pyrazine and 2H-Pyrano(2,3-b)pyrido(2,3-e)pyrazine Derivatives." ChemInform 28, no. 25 (August 3, 2010): no. http://dx.doi.org/10.1002/chin.199725152.

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28

Li, Ji-Cheng, Mi-Lim Hwang, Eun-Woo Lee, Soo-Hyoung Lee, Soo-Chang Yu, and Youn-Sik Lee. "Synthesis and Characterization of N-(2-Ethylhexyl)carbazole-2,3-Bis(4-fluorophenyl))thieno[3,4-b]pyrazine Copolymer." Bulletin of the Korean Chemical Society 31, no. 7 (July 20, 2010): 2073–76. http://dx.doi.org/10.5012/bkcs.2010.31.7.2073.

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29

Li, Wei, Junjun Tian, Xiujuan Qi, Kangcai Wang, Yunhe Jin, Binshen Wang, and Qinghua Zhang. "Synthesis of 4,8-Dinitraminodifurazano[3, 4-b,e ]pyrazine Derived Nitrogen-Rich Salts as Potential Energetic Materials." ChemistrySelect 3, no. 2 (January 16, 2018): 849–54. http://dx.doi.org/10.1002/slct.201702678.

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30

DALINGER, I. L., N. I. ZUBANOVA, V. S. KUZ'MIN, and S. A. SHEVELEV. "ChemInform Abstract: Nitropyrazoles. Part 2. Nitro Derivatives of Dipyrazolo(3,4-b:4′,3′-e) pyrazine (V), (VI)." ChemInform 25, no. 31 (August 19, 2010): no. http://dx.doi.org/10.1002/chin.199431176.

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31

Vedachalam, Murugappa, and Joseph H. Boyer. "2,6-Dithiodecahydro-1H,5H-Diimidazo[4,5,-b:4?,5?-e]Pyrazine and related dioxo- and diimino-decahydrodiimidazopyrazines." Heteroatom Chemistry 4, no. 1 (February 1993): 85–90. http://dx.doi.org/10.1002/hc.520040113.

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32

Zlotin, S. G., and A. V. Bobrov. "Synthesis of 5-bromo-4-dibromoamino-3-phenylisothiazole and its light-induced conversion into 3,7-diphenylbisisothiazolo[4,5-b:4′,5′-e]pyrazine." Russian Chemical Bulletin 49, no. 5 (May 2000): 956–57. http://dx.doi.org/10.1007/bf02494727.

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33

Mukherjee, Prasun, Asish Das, Raghwendra Mishra, Shovonlal Bhowmick, and Achintya Saha. "Synthesis of Novel tricyclic pyrazolo(1,4)oxathiinopyrazines and Evaluation of Their Competency Towards the Inhibition of Lactate Dehydrogenase Activity-Inhibition of LDH Activity." Drug Research 68, no. 11 (June 12, 2018): 653–60. http://dx.doi.org/10.1055/a-0630-4988.

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AbstractWe have evaluated the LDH inhibitory property of novel pyrazolo[4′,3′:5,6][1,4]oxathiino[2,3-b]pyrazine derivatives which have been synthesized from easily available starting materials through a one-pot protocol that offers the use of elemental sulfur as the sulfur source. These newly synthesized compounds may aid to drug development for neoplastic and non-neoplastic diseases characterized by increased glucose metabolism. Additionally, they may act as suitable starting materials which can be further structurally modified for the development of new LDH inhibitors with higher efficacy and specificity.

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34

Li, Ji-Cheng, Myung-Jin Beak, Jae-Teak Kwon, Eun-Woo Lee, Soo-Hyoung Lee, and Youn-Sik Lee. "Synthesis of poly(3-hexylthiophene-alt-2,3-bis(4-fluorophenyl)thieno[3,4-b]pyrazine) for polymer photovoltaic applications." Macromolecular Research 18, no. 12 (December 2010): 1237–40. http://dx.doi.org/10.1007/s13233-010-1211-8.

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35

Zlotin, Sergey G., Konstantin S. Chunikhin, and Marina O. Dekaprilevich. "Synthesis of 3,7-dichlorobisisothiazolo[4,5-b:4’,5’-e]pyrazine: the first representative of a new heterocyclic system." Mendeleev Communications 7, no. 3 (January 1997): 97. http://dx.doi.org/10.1070/mc1997v007n03abeh000727.

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36

Yamashita, Yoshiro, Kenichi Saito, Takanori Suzuki, Chizuko Kabuto, Toshio Mukai, and Tsutomu Miyashi. "Bis([1,2,5]thiadiazolo)[3,4-b;3?,4?-e]pyrazine, a Novel 14?-Electron Heterocycle with High Electron Affinity." Angewandte Chemie International Edition in English 27, no. 3 (March 1988): 434–35. http://dx.doi.org/10.1002/anie.198804341.

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37

Qin, Hongmei, Lisheng Li, Yang Li, Xiaobin Peng, Junbiao Peng, Yong Cao, Nurulla Ismayil, and Wei Shi. "Enhancing the performance of a thieno[3-4-b]pyrazine based polymer solar cell by introducing ethynylene linkages." European Polymer Journal 48, no. 12 (December 2012): 2076–84. http://dx.doi.org/10.1016/j.eurpolymj.2012.09.001.

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38

Klepp, Kurt O., Alan S. Cuthbertson, Peter M. Fischer, Jessie Sandoshamb, Michael Hartmann, Johann Hiebl, Hermann Kollmann, Peter Kremminger, and Franz Rovenszky. "The Crystal Structure of N,N′-Bis-(1,3-dihydroxy-2-methylprop-2-yl)- pyrazine-2,3-dicarboxamide Semihydrate." Zeitschrift für Naturforschung B 54, no. 8 (August 1, 1999): 1027–32. http://dx.doi.org/10.1515/znb-1999-0809.

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Crystals of the title compound were obtained by recrystallization of N,N′-bis-( 1,3-dihydroxy- 2-methylprop-2-yl)-pyrazine-2,3-dicarboxamide in aqueous methanol. C14H22N4O6 · 1/2H2O crystallizes in the triclinic system, s.g. P1̄ (No. 2) with a = 9.339(4) Å, b = 13.218(9) Å, c = 14.5137(9) Å, α = 70.95(4)°, β = 87.66(4)°, ɣ = 87.13(4)°, Z = 4. Its crystal structure has been determined from diffractometer data and refined to a conventional R of 0.050 (4008 observations, 464 variable parameters). The structure contains two crystallographically independent molecules which are alternatingly stacked above each other along the [001]-direction. Extensive intermolecular hydrogen bonding between these stacks leads to the formation of slabs parallel to (010). The hydrate water is only loosely attached to one of the molecules and has no apparent influence on the stacking.

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39

Vedachalam, Murugappa, Vayalakkavoor T. Ramakrishnan, Joseph H. Boyer, Ian J. Dagley, Keith A. Nelson, Horst G. Adolph, Richard Gilardi, Clifford George, and Judith L. Flippen-Anderson. "Facile synthesis and nitration of cis-syn-cis-2,6-dioxodecahydro-1H,5H-diimidazo[4,5-b:4',5'-e]pyrazine." Journal of Organic Chemistry 56, no. 10 (May 1991): 3413–19. http://dx.doi.org/10.1021/jo00010a043.

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40

Ayudha, Vety Sri Harlinda, and Mokhamat Ariefin. "Synthesis and Characterization of Pyrazine Derived Compounds as Potential Materials for Hole Transporting Layer (HTL)." Jurnal Kimia Sains dan Aplikasi 23, no. 6 (May 19, 2020): 228–33. http://dx.doi.org/10.14710/jksa.23.6.228-233.

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Three simple compounds that have the potential as a hole transporting layer (HTL) based on pyrazine derivatives conjugated with electron donor groups in the form of triphenylamine have been successfully synthesized and characterized. The synthesis began with a substitution reaction at high temperatures between 4-bromoaniline and 4-iodoanisole to produce 4-bromo-N,N-bis(methoxyphenyl)-aniline, followed by substitution of bromo atoms with tributylstanum at low temperatures and inert atmosphere (N2) producing 4-methoxy-N-(4-(tributylstanyl)phenyl)aniline. The conjugation reaction was carried out through a Stille coupling reaction between 1,2-bis (4-bromophenyl)ethane-1,2-dione with 4-methoxy-N-(4-(tributylstanyl)phenyl) aniline at high temperatures with the aid of a Pd(PPh3)4 catalyst in an inert atmosphere (N2). The reaction was continued with the imination reaction with 3 compounds, i.e., 1,2-diaminobenzene, 3,3-diaminobenzidine and 2,3-diaminopiridin to produce three HTL compounds that were namely 4’,4”-(quinoxaline-2,3-diyl)bis (N,N-bis(4(methoxyphenyl)-[1,1’-biphenyl]-4-amine) (DNB), 4’,4’’’,4’’’’’,4’’’’’’’-([6,6’-biquinoxaline]-2,2’,3,3’-tetrayl) tetrakis(N,N-bis(4-methoxyphenyl)- [1,1’-biphenyl] -4-amine) (bDNB), and 4’,4’’’-(pyrido[2,3-b]pyrazine-2,3-diyl)bis(N,N-bis (4-methoxyphenyl)-[1,1’-biphenyl]-4-amine) (DNP). The optical and electrochemical properties of DNB, bDNB, and DNP were analyzed by UV-Vis and Differential Pulse Voltammetry (DPV). The optical and electrochemical properties show the energy levels of the HOMO and LUMO of the three compounds. Hence their potential can be estimated as HTL compounds. The three compounds show λmax of 348 nm, 356 nm, and 350 nm for DNB, bDNB, and DNP. Based on DPV results, the HOMO values for DNB, bDNB, and DNP are -5.03 eV, -5.02 eV, and -4.98 eV and LUMO values of -2.46 eV, -2.76 eV and -2.87 eV, respectively. The three compounds' thermal properties were analyzed using TGA, with the results showing that the three compounds had good thermal resistance with a decomposition point above 400°C. Based on optical, electrochemical, and thermal analysis, DNB and bDNB have almost the same properties. Thus, it is expected that the three compounds have the potential as HTL material, with DNB and bDNB better than DNP.

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41

Zlotin, S. G., and A. V. Bobrov. "ChemInform Abstract: Synthesis of 5-Bromo-4-dibromoamino-3-phenylisothiazole and Its Light-Induced Conversion into 3,7-Diphenylbisisothiazolo[4,5-b:4′,5′-e]pyrazine." ChemInform 31, no. 47 (November 21, 2000): no. http://dx.doi.org/10.1002/chin.200047152.

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42

BATTISTINI, M., E. ERBA, and D. POCAR. "ChemInform Abstract: γ-Triazolines. Part 33. Synthesis of 3-Aminoquinoxaline 1-Oxides and 2-Aminopyrido(3,4-b)pyrazine 4-Oxides." ChemInform 24, no. 23 (August 20, 2010): no. http://dx.doi.org/10.1002/chin.199323214.

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43

VEDACHALAM, M., V. T. RAMAKRISHNAN, J. H. BOYER, I. J. DAGLEY, K. A. NELSON, H. G. ADOLPH, R. GILARDI, C. GEORGE, and J. L. FLIPPEN-ANDERSON. "ChemInform Abstract: Facile Synthesis and Nitration of cis-syn-cis-2,6-Dioxodecahydro-1H,5H- diimidazo(4,5-b:4′,5′-e)pyrazine." ChemInform 22, no. 39 (August 22, 2010): no. http://dx.doi.org/10.1002/chin.199139179.

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44

Foize Ahmad, G., A. Syed Mohammed Mujaheer, M. NizamMohideen, M. Gulam Mohamed, and V. Viswanathan. "The crystal structures and Hirshfeld surface analysis of 6-(naphthalen-1-yl)-6a-nitro-6,6a,6b,7,9,11a-hexahydrospiro[chromeno[3′,4′:3,4]pyrrolo[1,2-c]thiazole-11,11′-indeno[1,2-b]quinoxaline] and 6′-(naphthalen-1-yl)-6a′-nitro-6′,6a′,6b′,7′,8′,9′,10′,12a′-octahydro-2H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one." Acta Crystallographica Section E Crystallographic Communications 75, no. 10 (September 27, 2019): 1519–24. http://dx.doi.org/10.1107/s205698901901291x.

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The title compounds, 6-(naphthalen-1-yl)-6a-nitro-6,6a,6 b,7,9,11a-hexahydrospiro[chromeno[3′,4′:3,4]pyrrolo[1,2-c]thiazole-11,11′-indeno[1,2-b]quinoxaline], C37H26N4O3S, (I), and 6′-(naphthalen-1-yl)-6a′-nitro-6′,6a′,6b′,7′,8′,9′,10′,12a′-octahydro-2H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one, C36H28N2O4, (II), are new spiro derivatives, in which both the pyrrolidine rings adopt twisted conformations. In (I), the five-membered thiazole ring adopts an envelope conformation, while the eight-membered pyrrolidine-thiazole ring adopts a boat conformation. An intramolecular C—H...N hydrogen bond occurs, involving a C atom of the pyran ring and an N atom of the pyrazine ring. In (II), the six-membered piperidine ring adopts a chair conformation. An intramolecular C—H...O hydrogen bond occurs, involving a C atom of the pyrrolidine ring and the keto O atom. For both compounds, the crystal structure is stabilized by intermolecular C—H...O hydrogen bonds. In (I), the C—H...O hydrogen bonds link adjacent molecules, forming R 2 2(16) loops propagating along the b-axis direction, while in (II) they form zigzag chains along the b-axis direction. In both compounds, C—H...π interactions help to consolidate the structure, but no significant π–π interactions with centroid–centroid distances of less than 4 Å are observed.

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45

Yang, Tongtong, Zhibin Xu, and Zihui Meng. "Stability Study of Poly Nitro Substituted Compounds of cis-syn-cis-2,6-Dioxodecahydro-lH,5H-Diimidazo[4,5-b:4’,5’-e] Pyrazine." IOP Conference Series: Earth and Environmental Science 295 (July 25, 2019): 032100. http://dx.doi.org/10.1088/1755-1315/295/3/032100.

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46

Angibaud, P., O. Querolle, V. Berdini, G. Saxty, A. Cleasby, H. Colombel, I. Csoka, et al. "356 Discovery of novel pyrido[2,3-b]pyrazine as fibroblast growth factor receptor (FGFR-1, 2, 3 & 4) kinase inhibitors with nanomolar affinity." European Journal of Cancer 50 (November 2014): 115. http://dx.doi.org/10.1016/s0959-8049(14)70482-4.

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47

Childs, Bradley J., John M. Cadogan, Donald C. Craig, Marcia L. Scudder, and Harold A. Goodwin. "Electronic and Structural Properties of Iron(II) and Nickel(II) Cationic Complexes of 2-(Pyrazin-2-ylamino)-4-(pyridin-2-yl)thiazole." Australian Journal of Chemistry 50, no. 2 (1997): 129. http://dx.doi.org/10.1071/c96185.

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Complex salts containing the [FeIIN6]2+ derivative of 2-(pyrazin-2-ylamino)-4-(pyridin-2-yl)thiazole (pzaptH) undergo continuous, temperature-induced singlet (1A1) quintet (5T2) transitions with the transition temperature being dependent on the nature of the counter anion and the presence of solvate water, the latter tending to stabilize the singlet state. A transition is also observed for the fluoroborate salt in methanol solution. The extent of stabilization of the singlet state for iron(II) in these complexes is somewhat greater than in those derived from the previously studied 2-(pyridin-2-ylamino)-4-(pyridin-2-yl)thiazole. The crystal structures of [Fe(pzaptH)2] [CF3SO3]2 and [Ni(pzaptH)2] [BF4]2.2H2O have been determined. The average Fe-N distance is 1·985 Å, a value consistent with the essentially low-spin nature of the complex at room temperature, and the average Ni-N distance is 2·089 Å. In both complexes the bridging >NH group is involved in hydrogen bonding to the anions and, in the nickel complex, also to the solvate water. The uncoordinated nitrogen of the pyrazine ring is not hydrogen-bonded. Bis[2-(pyrazin-2-ylamino)-4-(pyridin-2-yl)thiazole]iron(II) triflate: triclinic, space group P -1, a 8·794(5), b 11·082(6), c 17·49(1) Å, α 77·59(4), β 86·80(4), γ 84·21(4)°, Z 2. Bis[2-(pyrazin-2-ylamino)-4-(pyridin-2-yl)thiazole]nickel(II) tetrafluoroborate dihydrate: monoclinic, space group P 21/c, a 8·784(3), b 8·795(2), c 41·16(1) Å, β 94·58(2)°, Z 4.

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48

Zyuzin, Igor N., Kyrill Yu Suponitsky, and Aleksei B. Sheremetev. "2,2-Bis(methoxy-NNO-azoxy)ethyl Derivatives of 4,8-Dihydro-bis-furazano[3,4-b:3′4′-e]pyrazine: The Synthesis and X-ray Investigation." Journal of Heterocyclic Chemistry 49, no. 3 (May 2012): 561–65. http://dx.doi.org/10.1002/jhet.811.

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49

Volovenko, Yu M., and G. G. Dubinina. "ChemInform Abstract: Synthesis of 6-Amino-5-R2-7- (6-R1-4-oxo-3,4-dihydro-2-quinazolyl)-5H-pyrrolo [2,3-b]pyrazine-2,3-dicarbonitriles." ChemInform 33, no. 43 (May 19, 2010): no. http://dx.doi.org/10.1002/chin.200243192.

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50

Vedachalam, Murugappa, Vayalakkavoor T. Ramakrishnan, and Joseph H. Boyer. "Dense compounds of C, H, N, and O atoms: Nitramine derivatives of diimino- and dioxodecahydro-1h,5h-diimidazo-[4,5-b:4?,5?-e]pyrazine." Heteroatom Chemistry 2, no. 2 (April 1991): 313–18. http://dx.doi.org/10.1002/hc.520020214.

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