Green synthesis of novel hexahydroquinolines and 6-amino-2-oxopyridine-3,5-dicarbonitriles incorporating sulfaguanidine via [3 + 3] atom combination
Amr M. Abdelmoniem, Mostafa E. Salem, Mahmoud Allam, Mortaga M. Abou–Krisha, Ibrahim O. Althobaiti, Said A. S. Ghozlan, Khaled E. Azmy, Ismail A. Abdelhamid
Abstract
The synthesis of sulfa drugs has received extensive interest from researchers for their broad spectrum of biological activities. In this context, N -Carbamimidoyl-4-((5,5-dimethyl-3-oxocyclohex-1-en-1-yl)amino)benzenesulfonamide 3 was readily prepared and its Michael addition reactions towards activated cinnamonitriles were studied as a route to 4-(2-amino-3-cyano-4-aryl-tetrahydroquinolin-1-yl)- N -carbamimidoylbenzenesulfonamide derivatives 8a-d . Moreover, N -(4-( N -carbamimidoylsulfamoyl)phenyl)-2-cyanoacetamide 13 was prepared and employed as a precursor for the synthesis of 4-(6-amino-3,5-dicyano-2-oxo-4-arylpyridin-1-yl)- N -carbamimidoylbenzenesulfonamide derivatives 17a-e . Green synthesis of the targeted products was done in water in the presence of chitosan as a green catalyst and gave considerably higher yields as compared to conducting reactions in ethanol in presence of non-benign piperidine catalyst. The chemical constitution of all newly synthesized compounds was confirmed by the different spectral tools.