Synthesis and crystal structure of 2-(2-hy-droxy-phen-yl)-1,3-bis-(4-meth-oxy-benz-yl)-1,3-diazinan-5-ol

Abstract

The redetermined structure of 2-(2-hy-droxy-phen-yl)-1,3-bis-(4-meth-oxy-benz-yl)-1,3-diazinan-5-ol, C₂₆H₃₀N₂O₄, at 173 K has ortho-rhom-bic (Pbca) symmetry. It was previously described by Bolte et al. [ Private Communication (refcode EWICEV). CCDC, Cambridge, England]. The title compound resulted from the condensation reaction between 1,3-bis-{[(4-meth-oxy-phen-yl)meth-yl]amino}-propan-2-ol and 2-hy-droxy-benzaldehyde in CH₃OH. The structure exhibits disorder. One of the 4-meth-oxy-benzyl groups, the hy-droxy group bonded to the 1,3-diazinan ring, and the methyl group of the meth-oxy residue are disordered over two orientations, with occupancies of 0.807 (3)/0.193 (3), 0.642 (5)/0.358 (5), and 0.82 (4)/0.18 (4), respectively. The dihedral angles between the mean planes of the central 1,3-diazinan-5-ol and the 4-meth-oxy-phenyl rings (both occupancy components of the disordered ring) are 88.65 (13), 85.79 (14) and 83.4 (7)°. The crystal packing is sustained by C-H⋯O and O-H⋯π inter-actions, giving rise to infinite chains running along the b-axis direction.

Keywords: C—H⋯O inter­actions; Mannich-type bases; O—H⋯π inter­actions; crystal structure; hexa­hydro­pyrimidine; intra­molecular hydrogen bond.