3-Aminopyrazine-2-carboxylic acid.

3-Aminopyrazine-2-carboxylic acid, C5H5N3O2, displays an extensive network of intra- and intermolecular hydrogen bonds which are undoubtedly responsible for the modest values of the displacement parameters. H-atom transfer to the ring N atoms did not occur and the carboxy and amino H atoms are ordered. The virtually planar molecules lie very nearly in planes parallel to (102) and are stacked along the a direction with separations of 3.324 (2) A indicating pi-pi interactions.