6-Amino-2,5-bis-(pivaloylamino)pyrimidin-4(3H)-one dihydrate.

The asymmetric unit of the title compound, C(14)H(23)N(5)O(3)·2H(2)O, contains two crystallographically independent 6-amino-2,5-bis-(pivaloylamino)pyrimidin-4(3H)-one mol-ecules (A and B) with similar geometry and four water mol-ecules. In both independent mol-ecules, one of the amide groups is almost coplanar with the pyrimidine ring [dihedral angle of 12.85 (9) in A and 12.30 (10)° in B], whereas the other amide group is significantly twisted away from it [dihedral angle is 72.18 (7) in A and 71.29 (7)° in B]. In each independent mol-ecule, an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. Mol-ecules A and B are linked into chains along the a axis by N-H⋯O and C-H⋯O hydrogen bonds. Adjacent chains are linked into a two-dimensional network parallel to the ac plane by water mol-ecules via N-H⋯O and O-H⋯O hydrogen bonds.