1-Piperaz-COO(Bz), thienyl urethane deriv. 1-Piperazinecarboxylic acid, 3-[[(1,1-dimethylethyl)amino]carbonyl]-4-[(2R,3S)-2-hydroxy-4-phenyl-3-[[[[(3S)-tetrahydro-3-furanyl]oxy]carbonyl]amino]butyl]-, phenylmethyl ester, (3S)- AIDS-032524 AIDS032524 L-735,524 analog