Potential amoebicidal activity of hydrazone derivatives: synthesis, characterization, electrochemical behavior, theoretical study and evaluation of the biological activity.

Four new hydrazones were synthesized by the condensation of the selected hydrazine and the appropriate nitrobenzaldehyde. A complete characterization was done employing 1H- and 13C-NMR, electrochemical techniques and theoretical studies. After the characterization and electrochemical analysis of each compound, amoebicidal activity was tested in vitro against the HM1:IMSS strain of Entamoeba histolytica.

Crystal structure of (E)-1-(2-nitro-benzyl-idene)-2,2-di-phenyl-hydrazine.

The title compound, C19H15N3O2, shows an E conformation of the imine bond. The dihedral angle between the planes of the phenyl rings in the di-phenyl-hydrazine groups is 88.52 (4)°.

(E)-1,1-Diphenyl-2-(thio-phen-2-yl-methyl-idene)hydrazine.

The asymmetric unit of the title compound, C17H14N2S, consists of two crystallographically independent mol-ecules with similar conformations. The dihedral angles between the phenyl rings are 89.32 (5) and 82.

(E)-1-(2,4-Di-nitro-benzyl-idene)-2,2-di-phenyl-hydrazine.

In the crystal of the title compound, C19H14N4O4, the asymmetric unit consists of two discrete mol-ecules. The C=N bonds in both mol-ecules show an E conformation. The dihedral angles between the C atoms of the 2,4-dinitrobenzene rings and the C=N-N planes are 13.

1-{(E)-[5-(2-Nitro-phen-yl)furan-2-yl]methyl-idene}-2,2-diphenyl-hydrazine.

In the title compound, C23H17N3O3, the terminal benzene rings are oriented at dihedral angles of 3.67 (7), 76.02 (7) and 16.

(E)-1-(4-Nitro-benzyl-idene)-2,2-diphenyl-hydrazine.

The asymmetric unit of the title compound, C(19)H(15)N(3)O(2), contains two mol-ecules, both of which show an E conformation of the imine bond. The dihedral angles between the phenyl rings in the phenyl-hydrazine groups are 86.09 (6) and 83.

(E)-1-Benzyl-idene-2,2-diphenyl-hydrazine.

The asymmetric unit of the title compound, C(19)H(16)N(2), contains two independent mol-ecules, both of which show an E configuration with respect to the C=N bond. The dihedral angles between the phenyl rings bonded to the hydrazine group are 81.00 (10) and 88.

(E)-1-(3,4-Dimethyl-benzyl-idene)-2,2-diphenyl-hydrazine.

The asymmetric unit of the title compound, C(21)H(20)N(2), contain two mol-ecules, both of them showing an E configuration of the C=N bond. The dihedral angles between the phenyl rings in the phenyl-hydrazone groups are 86.84 (10) and 84.

(1E,2E)-1,2-Bis(2,2-diphenyl-hydrazin-1-yl-idene)ethane.

In the crystal structure of the title compound, C(26)H(22)N(4), the mol-ecule is located on an inversion centre and shows an E configuration with respect to each C=N bond. The dihedral angle between the phenyl rings in the diphenyl-hydrazone group is 83.69 (11)°.

N'-[5-(4-Nitro-phen-yl)furan-2-yl-methyl-idene]-N,N-diphenyl-hydrazine.

The title compound, C(23)H(17)N(3)O(3), has an E configuration with respect to the C=N bond. The dihedral angle between the two phenyl rings bonded to the hydrazine group is 86.45 (13)°.