This report describes an improved synthesis of enantiomerically pure (S)-2-
-phenyl]-1-piperazinyl]propyl]-1,3-dioxo-1H-isoindole-5-carboxamide (RWJ 69
442), a potent and selective alpha (1a)-adrenergic receptor antagonist for
the treatment of benign prostatic hyperplasia. The synthesis highlights les
s hazardous reagents, easier purification and higher enantiomeric purity. T
he N-benzyl-N-t-butoxycarbonyl amine 6 could serve as an enantiomerically p
ure chiral building block for asymmetric synthesis.