Pyrazines and benzo derivatives

Pyrazine derivatives were again popular as ligands in crystallographic studies of transition metal complexes. These complexes included silver(I) alkylpyrazine sulfonates 83 07IC7299 , tetrakis[3-(pyrazin-2-yloxy)pyridinc-AiVJdithiocyanatomanganese 07AX(E)m441 , 

P°ly[[aqua(pyrazine-2-carboxylato)iron(II)]-//-pyrazine-2-carboxylato] 85 07AX(E)ml69 , 

Pyrazine-based heterocycles examined by X-ray crystallography included N,N -bis[2-(2-pyridyl)ethyl]pyrazine-2,3-dicarboxamide 07JCS(D)633 , diimidazo[l,5-a T,5 -J]pyrazine- 

Diels-Alder reactions of 2(T7/)-pyrazinones 94 and ethene gave cycloaddition products that were converted into 5-aminopiperidinone-2-carboxylates 07EJO965 . 

Zimhony, C. Vilcheze, M. Arai, J.T. Welch, W.R. Jacobs, Jr., Antimicrob. Agents Chemother. 

Our understanding of the physicochemical properties of pyrazines has deepened. The internal rotation and IR spectrum of 2,5-pyrazinedicarboxamide were studied by quantum chemical calculations 05TC73 , and ab initio MO calculations at the MP2/6-31++G( ) level were used to explain the electronic and vibrational properties of complexes of pyrazine and HX linear acids 05JMS2822 . MM and MO calculations were used to investigate the conformational and electronic properties of odor-active pyrazines 05JMS169 , and NMR, IR, X-ray, and DFT methods were used to examine the structures of pyridol l,2-a pyrazinium bromide 05JMS7 . 

Hamasaki, K. Hirano, C. Abe, K. Onozaki, Antimicrob. Agents Chemother. 2005, 49, 804. 

Andrei, R. Sienaert, C. McGuigan, E. De Clercq, J. Balzarini, R. Snoeck, Antimicrob. 

Abarca, R. Aucejo, R. Ballesteros, M. Chadlaoui, E. Garcia-Espana, C.R. de Arellano, Arkivoc 2005, 71. 

Sirivolu, J. He, H. Eickmeier, Acta Crystallogr., Sect. C Cryst. Struct. Commun. 2005, C61, o67. 

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