3-[3-(2,6-dioxo-1,3-dipropyl-7H-purin-8-yl)propylcarbamoyl]benzenesulfonyl fluoride 3-[[3-(2,6-dioxo-1,3-dipropyl-7H-purin-8-yl)propylamino]-oxomethyl]benzenesulfonyl fluoride 3-[3-(2,6-diketo-1,3-dipropyl-7H-purin-8-yl)propylcarbamoyl]benzenesulfonyl fluoride