Sodium 4-amino-5-hydroxy-7-sulfonaphthalene-2-sulfonate an efficient ligand for click reaction in water: Synthesis of 1,2,3-triazole pharmacophore linked-quinazolinone scaffold

Water soluble sodium 4-amino-5-hydroxy-7-sulfonaphthalene-2-sulfonate ligand was used successfully for the preparation of 1,2,3-triazoles pharmacophore linked-quinazolinone scaffold. The reaction of ethyl 4-oxo-3,4-dihydroquinazoline-2-carboxylate and related amide compounds with propargyl bromide afforded ethyl 4-oxo-3-(prop-2-yn-1-yl)-3,4-dihydroquinazoline-2-carboxylate and its amide derivatives. The reaction of propargylated compounds with azides catalyzed by copper (II) salt, in the presence of Sodium 4-amino-5-hydroxy-7-sulfonaphthalene-2-sulfonate as a ligand in water produced novel 1,2,3-triazole pharmacophore linked-quinazolinone-4-one scaffold with high-to-excellent yields. The ligand assisted in the click reaction and reduced loading of copper salt to 2 mol%. Simplicity, short reaction times, use of water as green solvent, and low catalyst loading are the main advantages of this procedure.