Planarity of benzoylthiocarbazate tuberculostatics. III. Diesters of 3-(2-hydroxybenzoyl)dithiocarbazic acid.

Searches for new tuberculostatic agents are important considering the occurrence of drug-resistant strains of Mycobacterium tuberculosis. The structures of three new potentially tuberculostatic compounds, namely isopropyl methyl (2-hydroxybenzoyl)carbonohydrazonodithioate, C12 H16 N2 O2 S2 , (Z)-benzyl methyl (2-hydroxybenzoyl)carbonohydrazonodithioate, C16 H16 N2 O2 S2 , and dibenzyl (2-hydroxybenzoyl)carbonohydrazonodithioate propan-2-ol monosolvate, C22 H20 N2 O2 S2 ·C3 H8 O, were determined by X-ray diffraction. The mutual orientation of the three main fragments of the compounds, namely an aromatic ring, a dithioester group and a hydrazide group, can influence the biological activity of the compounds. In all three of the structures studied, the C(=O)NH group is in the anti conformation. In addition, the presence of the hydroxy group in the ortho position of the aromatic ring in all three structures leads to the formation of an intramolecular hydrogen bond stabilizing the planarity of the molecules.