7-Chloro-4-[(E)-2-(3,4,5-trimeth-oxy-benzyl-idene)hydrazin-1-yl]quinoline.

In the title compound, C(19)H(18)ClN(3)O(3), the r.m.s. deviation through the 23 non-H and non-meth-oxy atoms is 0.088 Å, indicating a planar mol-ecule with the exception of the meth-oxy groups. One meth-oxy group, surrounded on either side by the other meth-oxy groups, is almost normal to the benzene ring to which it is connected [C-O-C(ar)-C(ar) torsion angle = 81.64 (15)°]. In the crystal, N-H⋯O, C-H⋯O and π-π inter-actions [between quinoline residues; centroid-centroid distance = 3.4375 (8) Å] link mol-ecules into a three-dimensional architecture.

4-[(E)-2-(2,4-Dichloro-benzyl-idene)hydrazin-1-yl]quinolin-1-ium chloride monohydrate.

In the title hydrated salt, C(16)H(12)Cl(2)N(3) (+)·Cl(-)·H(2)O, there is a small twist in the cation as seen in the torsion angle linking the benzene ring to the rest of the mol-ecule [171.96 (17)°]. In the crystal, the quinolinium H atom forms a hydrogen bond to the lattice water mol-ecule, which also forms hydrogen bonds to two Cl(-) anions. Each Cl(-) ion also accepts a hydrogen bond from the hydrazine H atom. The three-dimensional architecture is also stabilized by π-π inter-actions between centrosymmetrically related quinoline residues [centroid-centroid distance = 3.5574 (11) Å].

7-Chloro-4-[(E)-2-(2,5-dimeth-oxy-benzyl-idene)hydrazin-1-yl]quinoline.

In the nearly planar title compound (r.m.s. deviation for the 24 non-H atoms = 0.064 Å), C(18)H(16)ClN(3)O(2), the conformation about the N=C bond is E. Supra-molecular chains propagated by glide symmetry along [001] are found in the crystal packing. These are sustained by N-H⋯N hydrogen bonds with the quinoline N atom being the acceptor. The chains are connected into a three-dimensional architecture by π-π inter-actions involving all three aromatic rings [centroid-centroid distances = 3.5650 (9)-3.6264 (9) Å].

4-[(E)-2-(2-Chloro-benzyl-idene)hydrazin-1-yl]quinolin-1-ium chloride dihydrate.

In the title hydrated salt, C(16)H(13)ClN(3) (+)·Cl(-)·2H(2)O, a small twist is evident in the cation so that the chloro-benzene ring is not coplanar with the central hydrazinyl group [the N-C-C-C torsion angle = -4.8 (12)°]. The conformation about the imine N=C bond [1.284 (10) Å] is E. The components of the structure are connected into a three-dimensional architecture via O-H⋯O, O-H⋯Cl and N-H⋯Cl hydrogen bonds. One water H atom is disposed over two sites of equal occupancy.

Synthesis and anti-mycobacterial activity of (E)-N'-(monosubstituted-benzylidene)isonicotinohydrazide derivatives.

A series of 22 (E)-N'-(monosubstituted-benzylidene)isonicotinohydrazide derivatives have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H(37)Rv using Alamar Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC) in mug/mL. Compounds 2f, 2g, 2j, 2k and 2q exhibited a significant activity (0.31-0.62 microg/mL) when compared with first line drugs such as isoniazid (INH) and rifampicin (RIP) and could be a good starting point to develop new lead compounds in the fight against multi-drug resistant tuberculosis.

Synthesis and biological aspects of mycolic acids: an important target against Mycobacterium tuberculosis.

Mycolic acids are an important class of compounds, basically found in the cell walls of a group of bacteria known as mycolata taxon, exemplified by the most famous bacteria of this group, the Mycobacterium tuberculosis (M. tb.), the agent responsible for the disease known as tuberculosis (TB). Mycolic acids are important for the survival of M. tb. For example, they are able to help fight against hydrophobic drugs and dehydration, and also allow this bacterium to be more effective in the host's immune system by growing inside macrophages. Due to the importance of the mycolic acids for maintenance of the integrity of the mycobacterial cell wall, these compounds become attractive cellular targets for the development of novel drugs against TB. In this context, the aim of this article is to highlight the importance of mycolic acids in drug discovery.

2,4-Difluorobenzaldehyde benzoylhydrazone and 2,4-dichlorobenzaldehyde benzoylhydrazone are isostructural at 120 K with Z' = 2: complex sheets built from N-H...O, C-H...O and C-H...pi(arene) hydrogen bonds.

At 120 K, 2,4-difluorobenzaldehyde benzoylhydrazone, C14H10F2N2O, (I), and 2,4-dichlorobenzaldehyde benzoylhydrazone, C14H10Cl2N2O, (II), are isomorphous and isostructural in P2(1)/n with Z' = 2. In each structure, eight independent hydrogen bonds, viz. two of N-H...O type, five of C-H...O type and one of C-H...pi(arene) type, link the molecules into complex sheets, within which two independent one-dimensional substructures can be identified.