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In view of the rise of drug-resistant tuberculosis and difficult-to-treat related diseases caused by non-tuberculous mycobacteria, there is an urgent need for antimycobacterial drug discovery. <i>N</i>α-aroyl-<i>N</i>-aryl-phenylalanine amides (AAPs) have been identified as antimycobacterial agents and are subject to lead optimization. The aim of the present study is to evaluate the impact of <i>N</i>-aryl <i>ortho</i> cyano substitution in a lead compound on the crystal and molecular structure and its in vitro activity against <i>Mycobacterium abscessus</i>. The title AAP can be conveniently synthesized from <i>N</i>-Boc-protected <span style="font-variant: small-caps;">d</span>-phenylalanine in two amide coupling steps using a previously established racemization-free method. Two polymorphic forms in the solid-state are described, as discovered by X-ray and electron diffraction. The introduction of a cyano group in the <i>ortho</i> position of the AAP <i>N</i>-aryl ring, however, leads to loss of in vitro activity against <i>M. abscessus</i> subsp. <i>abscessus</i>.