Efficient amidation of weak amines: synthesis, chiral separation by SFC, and antimicrobial activity of N-(9,10-dioxo-9,10-dihydroanthracen-1-yl) carboxamide

An effective and straightforward method for the synthesis of 1-aminoanthracene-9,10-dione carboxamides by coupling a weakly reactive amine, 1-aminoanthracene-9,10-dione, and sterically hindered carboxylic acids was achieved using COMU as the coupling agent. Furthermore, making use of the advantages associated with the super-critical fluid chromatography (SFC) technique, a simplified and straightforward method for the chiral separation of optically active amide derivatives from the impurities associated with the reaction mixture, in a single step, was demonstrated. The antimicrobial activity of selected 1-aminoanthracene-9,10-dione carboxamides was studied. Advanced NMR and other spectral techniques were used for the thorough characterization of all the compounds. This study provides a general and simplified method for coupling a weak amine with a sterically hindered acid using COMU as a coupling agent, and demonstrates the separation of optically pure compounds from reaction related impurities in a single step using SFC, and identification of amide derivatives of 1-aminoanthracene-9,10-dione as potential antimicrobial agents.