Chonnam University Chemists Repurpose Dichloromethane for Amide Synthesis

Amide bonds serve as the fundamental architecture for proteins, medicines, and various polymers. Traditional synthesis methods typically rely on coupling reagents that are corrosive, produce hazardous waste, or prove difficult to scale. By utilizing dichloromethane under basic conditions, researchers found that carboxylates undergo an SN2 reaction to form reactive chloromethyl ester intermediates, which then react with amines to produce amides.

The team optimized the process using sodium carbonate as a base and dimethyl sulfoxide as a solvent, requiring 80 °C over 12 hours. This methodology demonstrated high efficacy in synthesizing pharmaceutical compounds, achieving a 92% yield for the antiarrhythmic agent procainamide and a 76% yield for the antidepressant moclobemide. Furthermore, the process proved scalable at the 100-millimole level, producing over 20 grams of moclobemide at 99% purity.

Published in the Journal of the American Chemical Society, the study highlights a significant shift toward green chemistry by repurposing a widely available solvent. By bypassing conventional stoichiometric reagents, this method reduces chemical waste while maintaining broad substrate scope, offering a practical pathway for large-scale chemical manufacturing.