155513-85-2Relevant academic research and scientific papers
Structural characterisation of 2,3-disubstituted pyrazines: NMR and X-ray crystallography
Farrán, M. ángeles,Claramunt, Rosa M.,López, Concepción,Pinilla, Elena,Torres, M. Rosario,Elguero, José
, p. 67 - 75 (2007/10/03)
2-Formyl-3-aminopyrazine (1), 2-acetyl-3-aminopyrazine (2) and 2-benzoyl-3-aminopyrazine (3) have been studied by multinuclear magnetic resonance spectroscopy in solution and in solid state. Amino-imine tautomerism in such derivatives has been discussed on the basis of the calculated stabilities of the different tautomers by the hybrid B3LYP/6-31G** method. The crystalline structure of compound 3 has been solved, it belongs to the monoclinic P21/n space group, and shows supramolecular architectures involving N-H?O and N-H?N-pyrazine intermolecular hydrogen bonds.
Dihalogentriphenylphosphoranes in the synthesis of heterocycles, 29. A simple synthesis of pteridin-4-ones, from methyl-3-amino-2-pyrazinecarboxylate and pyrazino[3,1]oxazin-4-ones
Wamhoff,Kroth
, p. 405 - 410 (2007/10/02)
Methyl 3-amino-2-pyrazinecarboxylate (3) affords the synthetically useful 3-aroylaminopyrazin-2-carboxylates 5a-f with aroyl chlorides, which are converted with dibromotriphenylphosphorane into 2-arylpyrazino[2,3-d][3,1]oxazin-4-ones 6a-f. Nucleophilic attack at the carbonyl function of these oxazinones results in ring cleaved amides which can be recyclized with dibromotriphenylphosphorane to afford 2-arylpteridin-4-ones 7a-f.
