Ethenzamide-gentisic acid-acetic acid (2/1/1)

Area of Science:

• Crystallography
• Materials Science
• Medicinal Chemistry

Background:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for pain and inflammation relief.
• Co-crystal formation is a strategy to improve the physicochemical properties of active pharmaceutical ingredients.
• Understanding molecular interactions in co-crystals is crucial for drug design.

Purpose of the Study:

• To characterize the crystal structure of a novel four-component co-crystal solvate.
• To investigate the intermolecular interactions stabilizing the co-crystal assembly.
• To explore the formation of supramolecular heterosynthons involving NSAIDs.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
• Hydrogen bonding interactions (N-H⋯O and O-H⋯O) were analyzed.
• π-π stacking interactions were identified and quantified.

Main Results:

• A four-component co-crystal solvate of ethenzamide, gentisic acid, and acetic acid (2:1:1 ratio) was successfully synthesized and characterized.
• Two symmetry-independent molecules of ethenzamide formed supramolecular acid-amide heterosynthons with gentisic acid and acetic acid.
• Strong O-H⋯O and N-H⋯O hydrogen bonds, along with π-π stacking, were identified as key stabilizing forces.

Conclusions:

• The study successfully elucidated the crystal structure and stabilization mechanisms of a novel NSAID-based co-crystal solvate.
• The formation of specific heterosynthons highlights the potential for rational co-crystal design.
• This research contributes to the understanding of solid-state properties of ethenzamide and gentisic acid, relevant for pharmaceutical development.