Crystal structure of 6,7-dihydroxy-6,7-dihydro-3H-imidazo[1,2-a]purin-9(5H)-one

Abstract

The title purine derivative, C7H7N5O3, is an adduct of guanine with glyoxal. In the molecule, the dihydroimidazole ring adopts a twisted conformation on the C—C bond, and the two hydroxyl groups lie on opposite sides of the mean plane of the ring. In the crystal, the molecules are linked by N—H...O, O—H...N and N—H...N hydrogen bonds forming a three-dimensional framework. The crystal packing is reinforced by C—H...O hydrogen bonds and by offset π–π stacking of the purine ring systems of inversion related molecules [intercentroid distance = 3.4839 (12) Å].