Three 2-(methysulfanyl)nicotinamides

Area of Science:

• Crystallography
• Organic Chemistry
• Molecular Structure

Background:

• Nicotinamide derivatives are important in medicinal chemistry.
• Understanding molecular conformations is key to predicting compound properties.
• Previous studies have explored various substituted nicotinamides.

Purpose of the Study:

• To compare the molecular conformations of three N-alkyl-2-(methylsulfanyl)nicotinamide derivatives with unsubstituted analogs.
• To investigate the influence of N-alkylation on the torsion angle between the pyridine ring and the amide group.
• To analyze the supramolecular structures and hydrogen bonding patterns in the crystalline state.

Main Methods:

• X-ray crystallography was used to determine the molecular structures.
• Comparison of dihedral angles between pyridine and amide groups.
• Analysis of intermolecular interactions, including hydrogen bonding and crystal packing.

Main Results:

• N-alkyl-2-(methylsulfanyl)nicotinamide derivatives showed significantly higher torsion angles (40-60°) compared to unsubstituted compounds (20-35°).
• Supramolecular structures in N-cyclohexyl and N-isopropyl derivatives were formed by amide-N to carbonyl-O chains.
• N-(2-hydroxyethyl)-2-(methylsulfanyl)nicotinamide dihydrate formed a 3D network via hydrogen bonds to water molecules.

Conclusions:

• N-alkylation, particularly with bulky groups, increases the torsion of the pyridine ring relative to the amide moiety.
• The nature of the N-alkyl substituent dictates the mode of self-assembly and supramolecular architecture.
• These findings provide insights into structure-property relationships for nicotinamide derivatives.