Synthesis, characterization and crystal structures of two new phenolic mannich bases

Abstract

Two new Mannich bases, 5-methyl-2-((4-(pyridin-2-yl)piperazin-1-yl)methyl)phenol (1) and 5-methyl-2-((4-(4-nitrophenyl)piperazin-1-yl)methyl)phenol (2), were prepared and characterized structurally with elemental analysis, IR, UV and NMR spectroscopic techniques as well as single crystal X-ray diffraction. Compound I crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 6.6726(2) Å, b =   17.0542(6)   Å, c = 13.3222(4) Å, β = 100.832(1)°, V = 1489.00 (8) ų, Z = 4, R₁ = 0.0408, wR₂ = 0.1143. Compound II crystallizes in the monoclinic space P21 with unit cell dimensions a = 5.9519(2) Å, b = 17.3315(8) Å, c = 15.7237(7) Å, β = 90.348(2)°, V = 1621.95(12) ų, Z = 4, R₁ = 0.0353, wR₂ = 0.0965. Both compounds have their structures stabilized by hydrogen bonding and π∙∙∙π interactions.

KEY WORDS: Mannich base, Piperazine, X-ray diffraction, Hydrogen bonds

Bull. Chem. Soc. Ethiop. 2019, 33(2), 341-348.

DOI: https://dx.doi.org/10.4314/bcse.v33i2.14