3-phenyl-4-(N-(p-tolyl)sulfamoyl)-1,2,3-oxadiazol-3-ium-5-olate

4-(N-(4-chlorophenyl)sulfamoyl)-3-phenyl-1,2,3-oxadiazol-3-ium-5-olate

3-phenyl-4-(N-(thiazol-2-yl)sulfamoyl)-1,2,3-oxadiazol-3-ium-5-olate

3-phenyl-4-sulfamoyl-sydnone

4-methoxysulfonyl-3-phenyl-sydnone