4-{2-[4-(1,3-Dibutyl-4,6-dioxo-2-thioxo-tetrahydro-pyrimidin-5-ylidene)-but-2-enylidene]-naphtho[2,1-d]thiazol-3-yl}-butane-1-sulfonic acid AIDS-165757 AIDS165757 S-067(*Triethylammonium salt*)