(R)-OHEturea isostere, Qua deriv. AIDS-004530 AIDS004530 N-tert-Butyl-N'-(4-pyridylmethyl)-N'-[[2(R)-hydroxy-4-phenyl-3(S)-[4-amino-1,4-dioxo-2(S)-(2-quinolinylcarboxamido)butylamino]butyl]urea