4-{2-[4-(1,3-Dibutyl-4,6-dioxo-2-thioxo-tetrahydro-pyrimidin-5-ylidene)-but-2-enylidene]-naphtho[1,2-d]thiazol-1-yl}-butane-1-sulfonic acid AIDS-165772 AIDS165772 S-071(*Sodium salt*)