3-{2-[4-(1,3-Dibutyl-4,6-dioxo-2-thioxo-tetrahydro-pyrimidin-5-ylidene)-but-2-enylidene]-5-phenyl-oxazol-3-yl}-propane-1-sulfonic acid AIDS-165753 AIDS165753 S-051(*Triethylammonium salt*)