3-(2-((6-Hydroxy-2-(((4-methoxyphenyl)(diphenyl)methyl)amino)-9H-purin-9-yl)methoxy)ethoxy)-8,8-dimethyl-3-oxido-7-oxo-2,4,6-trioxa-3-phosphanon-1-yl pivalate AIDS-149887 AIDS149887 NSC685585