Oxalamides are important structural fragments of a variety of biologically active substances including natural compounds and widely used drugs. In particular, unsymmetrically substituted N-aryl oxalamides attract a great attention in scientific community as promising chelating ligands in catalysis, potential therapeutic agents, and building blocks in organic synthesis. The known methods for their preparation have a number of disadvantages, such as the need of absolute solvents, harsh reaction conditions, and a limited substrates scope.
Researchers from Laboratory № 22 of the Institute of Organic Chemistry have developed an easy synthetic route to unsymmetrically substituted N-aryl oxalamides using inexpensive and available 2,2'-biphenyldiamines, 2-chloroacetamides, sulfur, and water as starting compounds. This approach significantly expands the range of synthetically available N-aryl oxalamides with NH2 group in the side chain. The developed synthetic route will be useful in pharmacological studies and in the search for ligands for use in transition metals-catalyzed reactions.
T. A. Tikhonova, N. V. Ilment, K. A. Lyssenko, I. V. Zavarzina, Yu. A. Volkova Sulfur-mediated synthesis of unsymmetrically substituted N-aryl oxalamides by the cascade thioamidation/cyclocondensation and hydrolysis reaction Org. Biomol. Chem., 2020, 18, 5050-5060, DOI: 10.1039/D0OB00811G