Crystal structure of the tetra-ethyl-ammonium salt of the non-steroidal anti-inflammatory drug nimesulide (polymorph II)

Abstract

The crystal structure of the tetra-ethyl-ammonium salt of the non-steroidal anti-inflammatory drug nimesulide (polymorph II) (systematic name: tetra-ethyl-ammonium N-methane-sulfonyl-4-nitro-2-phen-oxy-anilinide), C₈H₂₀N⁺·C₁₃H₁₁N₂O₅S^-, was determined using single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P2₁/c with one tetra-ethyl-ammonium cation and one nimesulide anion in the asymmetric unit. In the crystal, the ions are linked by C-H⋯N and C-H⋯O hydrogen bonds and C-H⋯π inter-actions. There are differences in the geometry of both the nimesulide anion and the tetra-ethyl-ammonium cation in polymorphs I [Rybczyńska & Sikorski (2023 ▸). Sci. Rep. 13, 17268] and II of the title compound.

Keywords: API; N-(4-nitro-2-phen­oxy­phen­yl)methane­sulfonamide; crystal structure; nimesulide; polymorphism; tetra­ethyl­ammonium salt.

Figure 1

Crystal structure of title compound with the atom-labeling scheme (displacement ellipsoids are drawn at the 25% probability level; hydrogen bonds are represented by dashed lines).

Figure 2

Comparison of the geometries of the nimesulide anion (a) and (b) and the tetra­ethyl­ammonium cation (c) and (d) in the crystals of the two polymorphs of the tetra­ethyl­ammonium salt of nimesulide.

Figure 3

Crystal packing of the title compound viewed along the b axis (inter­actions between nimesulide anions are highlighted in green, whereas inter­actions between the nimesulide anion and tetra­ethyl­ammonium cation are highlighted in orange).