Efficient one-pot synthesis of mono and bis-N-cyclohexyl-3-alkyl(aryl)-quinoxaline-2-amines using N-halo catalysts†
Abstract
A convenient synthetic protocol for the synthesis of mono- and bisquinoxalines involving a room temperature one-pot three-component Ugi reaction of aromatic amines, aromatic or aliphatic aldehydes and cyclohexyl isocyanide with N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] or poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) [PBBS] as catalysts has been developed. Thin-layer chromatography was used for purification of mono and bisquinoxalines. Mild reaction conditions, good to high yields, cheap and stable catalysts and short reaction times are some of the salient features of the protocol presented.