7,9-Bis(hy-droxy-meth-yl)-7H-purine-2,6,8(1H,3H,9H)trione

Abstract

The structure of the title uric acid derivative, C(7)H(8)N(4)O(5), from human kidney stones, is characterized by the C and O atoms of one of the two hy-droxy-methyl groups being disordered nearly equally over three different sites. In the crystal, mol-ecules are connected by a three-dimensional hydrogen-bonding scheme though they look stacked in planes nearly parallel to ([Formula: see text]04).

Fig. 1.

ORTEP view (Farrugia, 1997) of the title molecule; displacement ellipsoids are drawn at the 50% probability level. The nine hydrogen atoms bonded to C7, O71, O72 and O73, with ~1/3 occupancies are omitted for the sake of clarity.

Fig. 2.

DIAMOND (Brandenburg, 2001) projection of the structure along the a axis. The N1—H1···O6, N3—H3···O8 and O9—H9···O2 hydrogen bonds ensuring the formation of layers are represented by dashed lines. H atoms with ~1/3 occupancy are not represented.

Fig. 3.

DIAMOND (Brandenburg, 2001) projection of the structure along the b axis showing the layers stacked parallel to (104). H atoms with ~1/3 occupancy are not represented. The disordered OH group (O71, O72, O73) is mainly involved in inter-layers hydrogen bonding.