3-(3-Chlorophenyl)-4-(2'-benzimidazolomercaptoacetyl) sydnone, inner salt 4-[2-(1H-Benzoimidazol-2-ylsulfanyl)-acetyl]-3-(3-chloro-phenyl)-5-hydroxy-[1,2,3]oxadiazol-3-ium, inner salt AIDS-097984 AIDS097984