4OH Coumarin deriv. AIDS-028327 AIDS028327 Phenprocoumon, BOC-GlyNH deriv. [2-[[3-[1-(4-Hydroxy-2-oxo-2H-1-benzopyran-3-yl)propyl]phenyl]amino]-1-methyl-2-oxoethyl]carbamic acid, tert-butyl ester