Abstract An efficient methodology for obtaining 2-arylpyrimidines based on the use of p-sulfonic acid calixarene as an organocatalyst is proposed. The methodology involves the formation of 1,2-dihydropyridine intermediates using a variety of aromatic aldehydes with methyl or ethyl acetoacetate and ammonium acetate, which are the same starting materials as in the Hantzsch reaction, under solvent-free reaction conditions, at 25 °C, followed by air oxidation for 12h. The catalyst efficiency is not compromised after its successive use in reactions. Eleven examples were obtained with very good to excellent yields of 2-arylpyridines (92-62%). This is the first report about the use of calixarenes as catalysts in the multicomponent synthesis of 2-arylpyridines (molecules with potential biological activity).
Sathicq, Á. G., Liberto, N. A., Fernándes, S. A., & Romanelli, G. P. (2015). Solvent-free multicomponent synthesis of 2-arylpyridines using p-sulfonic acid calixarene as a reusable catalyst. Comptes Rendus Chimie, 18(4), 374–378. https://doi.org/10.1016/j.crci.2014.08.006