7-Amino-1,8-naphthyridin-2(1H)-one monohydrate

In the crystal structure of the title compound, C(8)H(7)N(3)O·H(2)O, adjacent organic mol-ecules are linked together into a tape along the a axis through N-H⋯N and N-H⋯O hydrogen bonds. On the other hand, water mol-ecules are linked together to form a chain along the b axis through O-H⋯O hydrogen bonds. The water chains and the organic mol-ecular tapes are further connected by inter-molecular O-H⋯O hydrogen bonds, forming a three-dimensional network. In addition, a π-π stacking inter-action between the 1,8-naphthyridine ring systems with an inter-planar separation of 3.246 (1) Å and a centroid-centroid distance of 3.825 (2) Å is observed.