Crystal structure of ebastinium 3,5-di-nitro-benzoate

Area of Science:

• Chemical Crystallography
• Organic Chemistry
• Pharmaceutical Science

Background:

• Ebastine is a non-sedating antihistamine used for allergic conditions.
• Salts of active pharmaceutical ingredients can modify physicochemical properties like solubility and stability.
• Understanding the solid-state structure of drug salts is crucial for formulation development.

Purpose of the Study:

• To synthesize and characterize the 1:1 salt formed between ebastine and 3,5-dinitrobenzoic acid.
• To elucidate the crystal structure of ebastinium 3,5-dinitrobenzoate.
• To investigate the intermolecular interactions within the crystal lattice.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
• Reaction in methanol solution was used for salt formation.
• Crystallographic data analysis included disorder modeling and hydrogen bond analysis.

Main Results:

• The title compound, ebastinium 3,5-dinitrobenzoate (C32H40NO2+·C7H3N2O6-), was successfully synthesized.
• The crystal structure revealed orientational disorder of a disubstituted aryl ring in the ebastine cation.
• The structure features an axial orientation of the bulky substituent on the piperidine ring.
• Intermolecular interactions, including N-H⋯O and C-H⋯O hydrogen bonds, form complex sheet-like structures.

Conclusions:

• The synthesis and structural characterization of ebastinium 3,5-dinitrobenzoate provide insights into the solid-state behavior of ebastine salts.
• The observed orientational disorder and hydrogen bonding network influence the crystal packing.
• This structural information is valuable for understanding the physical properties and potential formulation strategies for ebastine.