1,4-Dimethylpiperazin-1-ium 3-hydroxy-2-naphthoate

The reaction of 1,4-dimethyl-piperazine and 3-hy-droxy-2-naphthoic acid gives the title 1:1 salt, C(6)H(15)N(2) (+)·C(11)H(7)O(3) (-), with a singly protonated piperazinium cation. In the crystal, a single N-H⋯O hydrogen bond links the cations and anions into discrete pairs and the aromatic anions stack along the crystallographic a-axis direction. This results in layers of cations and anions alternating along the crystallographic c-axis direction. An intra-molecular O-H⋯O hydrogen bond is also present.