2-((5-(6-(5-((2-Hydroxyethyl)imino)-4-methyl-4,5-dihydro-1,3,4-thiadiazol-2-yl)-2-pyridinyl)-3-methyl-1,3,4-thiadiazol-2(3H)-ylidene)amino)ethanol AIDS-140954 AIDS140954 NSC655073