Crystal structure of propylthiouracil determined using high-resolution synchrotron X-ray powder diffraction

Abstract

The crystal structure of propylthiouracil, a drug used in the treatment of hyperthyroidism, was determined by means of high-resolution synchrotron X-ray powder diffraction data. The Rietveld method was employed to refine the structure. This drug crystallizes in an orthorhombic (Pcab) space group, with unit cell parameters a = 28.67338(23) Å, b = 11.15287(6) Å, c = 10.66821(5) Å, V = 3411.59(4) ų, Z = 16, Z′ = 2, M = 170.23 g mol⁻¹, ρ_calc = 1.3258(1) g cm⁻³. The goodness-of-fit and R-factors were, respectively: χ² = 1.599, R_Bragg = 1.57%, R_wp = 8.85% and R_exp = 5.53%. Four hydrogen bonds involving the atoms N(6)–H(12)⋯S(39), N(19)–H(21)⋯O(41), N(27)–H(33)⋯S(18) and N(40)–H(42)⋯O(20) form a network of molecular aggregates in propylthiouracil.