Two 1-(2-Furoyl)-3-phenylthiourea Derivatives: Synthesis, Characterization and Structural Study from X-ray Powder Diffraction Using Simulated Annealing

Abstract

1-(2-furoyl)-3-p-cyanophenylthiourea (1) and 1-(2-furoyl)-3-o-fluorophenylthiourea (2) were synthesized by converting 2-furoyl chloride into 2-furoyl isothiocyanate and then condensing with the appropriated aniline derivatives. Both products were characterized by elemental analysis, Fourier transform infrared spectroscopy, Raman, 1H, 13C nuclear magnetic resonance and ab initio X-ray powder structure analysis. Compound 1 crystallizes in the monoclinic space group P21/n with unit cell dimensions a = 23.169(2) A, b = 11.353(2) A, c = 4.798(3) A, β = 90.30(2)°, V = 1,259.87(3) A3, Z = 4, R p = 4.62, and R wp = 7.86. Compound 2 crystallizes also in the monoclinic space group P21/n with unit cell dimensions a = 12.072(1) A, b = 20.801(2) A, c = 4.737(2) A, β = 93.34(2)°, V = 1,189.62(3) A3, Z = 4, R p = 3.95, and R wp = 7.06. The crystal structures have been determined from laboratory X-ray powder diffraction data using direct space global optimization strategy (simulated annealing) followed by the Rietveld refinement. The thiourea group makes a dihedral angle of 9.4(5)° and 33.5(4)° with the furoyl group in 1 and 2, respectively. In both compounds, the trans–cis geometry of the thiourea unit is stabilized by intramolecular N–H⋯O hydrogen bond between the H atom of the cis thioamide and the carbonyl O atom. In the crystal structure of compound 1, molecules are linked by intermolecular N–H⋯S bonds, forming one-dimensional chains along the c axis. For compound 2, only Van der Waals interactions are observed in the crystal structure, forming one-dimensional chains along the b axis. Crystal structure analysis from X-ray powder diffraction data and spectroscopic characterization of two 1-(2-furoyl)-3-phenylthiourea derivatives.