6-[2-(4-Hydroxy-phenyl)-2-(5-isopropyl-6-thioxo-[1,3,5]thiadiazinan-3-yl)-ethanoylamino]-3,3-dimethyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid AIDS-016757 AIDS016757 NSC649777