Crystal structure of N′-hydroxypyrimidine-2-carboximidamide

The title compound, C5H6N4O, is approximately planar, with an angle of 11.04 (15)° between the planes of the pyrimidine ring and the non-H atoms of the carboximidamide unit. The molecule adopts anEconfiguration about the C=N double bond. In the crystal, adjacent molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with anR22(10) ring motif. The dimers are further linkedviaN—H...N and O—H...N hydrogen bonds into a sheet structure parallel to theacplane. The crystal structure also features N—H...O and weak C—H...O hydrogen bonds and offset π–π stacking interactions between adjacent pyrimidine rings [centroid–centroid distance = 3.622 (1) Å].