1,1′-(Piperazine-1,4-diyl)dipropan-2-ol

The asymmetric unit of the crystal contains one-fourth of the title compound, C10H22N2O2, with the centre of the piperazine ring located at a site of 2/m symmetry. The piperazine ring adopts a chair conformation. The methine and methylene C atoms of the 2-hydroxypropyl groups show symmetry-imposed disorder over two equally occupied and mutually exclusive sets of positions. Only intramolecular O—H⋯N contacts are observed.

The asymmetric unit of the crystal contains one-fourth of the title compound, C 10 H 22 N 2 O 2 , with the centre of the piperazine ring located at a site of 2/m symmetry. The piperazine ring adopts a chair conformation. The methine and methylene C atoms of the 2-hydroxypropyl groups show symmetry-imposed disorder over two equally occupied and mutually exclusive sets of positions. Only intramolecular O-HÁ Á ÁN contacts are observed.
The structure of the title compound is shown in Fig. 1. The structure contains one central piperazine ring (N1/C4/C4 i / N1 i /C4 ii /C4 iii ) with two propanol moieties substituted at the two N atoms of the piperazine ring. The centre of the ring located at a site of 2/m symmetry. The N, O and methyl C atoms are located on the mirror plane, while atoms C2 and C3 show symmetry-imposed disorder.
The molecular structure of the title compound contains two intramolecular O-H···N contacts, which form a fivemembered ring with graph-set descriptor S(5) (Bernstein et al., 1995). No intermolecular hydrogen bonds are observed in the crystal structure. Van der Waals forces stabilize the packing.

Experimental
Piperazine (1.50 g, 17.40 mmol) was dissolved in 50 ml argon saturated methanol. Methanol solution of 2.88 g (50.00 mmol) propylene oxide was added to the piperazine solution at room temperature. The solution was left under magnetic stirrer for 24 h. The solution volume was reduced by rotary evaporator and the oily product was left for crystallization.

Refinement
H atoms were positioned geometrically and treated using a riding model, fixing the bond lengths at 0.82, 0.93, 0.97 and 0.96 Å for OH, CH, CH 2 and CH 3 groups, respectively. The isotropic displacement parameters of the H atoms were constrained at 1.2 U eq of their parent atom (1.5 U eq for methyl and OH groups). Atoms C2 and C3 showed symmetry-imposed disorder and were refined anisotropically using ADP restraints (SIMU and DELU) and half occupancy.