A series of guanylsulfonamides, 2-amino-9-[2-substituted-4-(4-substituted piperidin-1- sulfonyl) phenyl]-1, 9-dihydropurin-6-ones, was synthesized by adopting reductive aminoformylation of 2-amino-5-nitro-6-[4-(piperidin-1-sulfonyl) phenylamino]-3H-pyrimidin-4- one and subsequent intramolecular ring condensation as key steps. All the guanylsulfonamides were assayed for their in vitro antibacterial activities against ...