SEARCH Articles Figures Tables 1-Pyrazolo pyrazine ring Aromatic pyrazine ring, production Pyrazine acid, ring synthesis Pyrazine ring 1,2,3,4-tetrahydro- from Pyrazine ring closure, oxidative Pyrazine ring coupling Pyrazine ring formation Pyrazine ring synthesis Pyrazine ring, amino Pyrazines ring synthesis Pyrazines ring transformations forming Ring Transformations of Pyridazines and Other Heterocycles to Pyrazines Ring contraction pyrazine rings Ring hydrogenation pyrazine rings