Crystal structure of 4-[4-(eth-oxy-carbon-yl)piperazin-1-yl]benzoic acid.

The asymmetric unit of the title compound, C14H18N2O4, contains two independent mol-ecules (A and B) which have essentially the same conformation. The piperazine rings adopts chair conformations with the N atoms out of plane. The dihedral angles formed by the four approximately planar C atoms of the piperazine ring and the benzene ring is 30.8 (5)° in mol-ecule A and 30.6 (5)° in mol-ecule B. In the crystal, mol-ecules A and B are connected by a pair of O-H⋯O hydrogen bonds, forming a dimer with graph-set notation R2(2)(8). Weak C-H⋯O hydrogen bonds connect the dimers, forming zigzag chains along [001].