AIDS-144919 AIDS144919 Diethyl 5-(3-ethoxy-3-oxopropyl)-8,11-bis(2-methoxy-2-oxoethyl)-3,6,9,12-tetraoxo-1-phenyl-2-oxa-4,7,10,13-tetraazahexadecane-14,16-dicarboxylate NSC668444