AZT-5'-(p-bromophenyl methoxyalaninyl phosphate) as a potent and non-toxic anti-human immunodeficiency virus agent.

The potency and selectivity index of the AZT-phenyl phosphate derivatives in thymidine kinase (TK)-deficient T cells were substantially enhanced by introducing a single para-bromo substitutent in the phenyl moiety. AZT-5'-(p-bromophenyl methoxyalaninyl phosphate) was 43-fold more potent than AZT-5'-(phenyl methoxyalaninyl phosphate) and was fivefold more potent than AZT in inhibiting human immunodeficiency virus (HIV) replication in TK-deficient CEM cells.