Sohail Saeed

Synthesis, characterization and biological evaluation of some thiourea derivatives bearing benzothiazole moiety as potential antimicrobial and anticancer agents.

Five series of thiourea derivatives bearing benzothiazole moiety (20 compounds) were efficiently synthesized and evaluated for antimicrobial and anticancer activities. The results indicated that the compounds possessed a broad spectrum of activity against the tested microorganisms and showed higher activity against fungi than bacteria. Compounds 1b, 2b, 3b, 4b and 5b exhibited the greatest antimicrobial activity. Preliminary study of the structure-activity relationship revealed that electronic factors in benzothiazole rings had a great effect on the antimicrobial activity of these compounds. In preliminary MTT cytotoxicity studies, the thiourea derivatives (2d, 5c and 5d) were found most potent. In MCF-7 and HeLa cells, the IC(50) values were observed in the range of 18-26 microM and 38-46 microM, respectively.

Synthesis, spectroscopic characterization, crystal structure and antifungal activity of thiourea derivatives containing a thiazole moiety

AbstractFour novel thiourea derivatives containing a thiazole moiety were synthesized and characterized by IR, 1H and 13C NMR, mass spectrometry and elemental analysis. The crystal structure of 1a was determined from single crystal X-ray diffraction data. It crystallizes in monoclinic space group P21/n with unit cell dimensions a = 11.7752(6) Å, b= 3.8677(2) Å, c= 27.4126(13) Å and β = 92.734(5) Å. There is a strong intramolecular hydrogen bond of the type N-H⋯O, with H⋯O distance of 2.5869(19) Å. The mass fragmentation pattern has also been discussed. The antifungal activity of the synthesized compounds was studied by broth micro-dilution method and poisoned food technique. The compounds 1b and 1c possessed a broad spectrum of antifungal activity.

Ethyl 4-(3-benzoyl-thio-ureido)benzoate.

The title compound, C17H16N2O3S, crystallizes in the thioamide form with an intramolecular N—H⋯O hydrogen bond across the thiourea system. Molecules are connected in chains parallel to [10] by hydrogen bonds from the second thiourea N—H group to the benzoate C=O function.

1-(4-Bromo­phen­yl)-1-(4-nitro­benzo­yl)thio­urea

The title compound, C14H10BrN3O3S, crystallizes as two concomitant polymorphs that differ in colour (one yellow and one colourless). Only the structure of the colourless form could be determined. The molecule exists in the thioamide form with an intramolecular N—H⋯O=C hydrogen bond across the thiourea system. Molecules are linked into layers parallel to (120) by Br⋯Onitro contacts [3.103 (1) Å], classical hydrogen bonds from the other NH function to the S atom and Nnitro⋯O=C contacts. The layers are linked by weak C—H⋯Onitro hydrogen bonds to produce the observed three-dimensional network.

Semiconducting nanostructured copper sulfide thin films from bidentate copper(II) complexes of N-(dialkylcarbamothioyl)-nitrosubstituted benzamides by chemical vapour deposition

Copper(II) complexes of various N-(dialkylcarbamothioyl)-nitrosubstituted benzamide [dialkyl = di-n-butyl (1a, 2a); hexyl, methyl (3a); butyl, ethyl (4a)] have been synthesized and characterized by elemental analysis, IR spectroscopy and atmospheric pressure chemical ionization-mass spectrometry (MS-APCI). The molecular structure of the complex 2a was determined by single-crystal X-ray diffraction. These complexes were used as single-source precursors for the deposition of copper sulfide thin films by aerosol assisted chemical vapour deposition (AA-CVD) at 350 °C. The powder X-ray diffraction (p-XRD) patterns of the thin films of complexes 3a and 4ashowed the deposition of rhombohedral digenite Cu9S5 phase, and complex 1a deposited monoclinic roxbyite Cu7S4 phase at 350 °C with spherical crystallites. Complex 2a deposited orthorhombic anilite Cu7S4 phase with spherical crystallites. The degree of roughness of the film surface was determined by atomic force microscopy (AFM). The scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) results showed the uniform distribution of copper sulfide in the films, which makes them useful semiconducting materials on a structured surface.

Nickel(II) complexes of N-(dialkylcarbamothioyl)-4-nitrobenzamide as single-source precursors for the deposition of nanostructured nickel sulfide thin films by chemical vapor deposition

Nickel(II) complexes of N-(di-alkyl-carbamothioyl)-4-nitrobenzamide (alkyl = ethyl or n-propyl) have been synthesized and characterized by infrared spectroscopy, elemental analysis, nuclear magnetic resonance spectroscopy, and mass spectrometry. The structures of bis[N-(diethylcarbamothioyl)-4-nitrobenzamide]nickel(II) (2a) and bis[N-(dipropylcarbamothioyl)-4-nitrobenzamide]nickel(II) (2b) have been determined by X-ray crystallography. FTIR and NMR of the nickel complexes showed the absence of the N–H proton resonance and the N–H stretch and shift of ν C=O and ν C=S as expected. Both complexes have been used as single-source precursors for the deposition of nickel sulfide nanostructured thin films by aerosol-assisted chemical vapor deposition. The nanostructured thin films were characterized by X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and atomic force microscopy.

Ethyl 4-(3-butyrylthio-ureido)benzoate.

The title compound, C14H18N2O3S, crystallizes in the thioamide form with an intramolecular N—H⋯O hydrogen bond associated with the thiourea unit. With the benzoic acid and the butyrylthioureido units, the molecule consists of two planar building blocks connected by the common NH function adjacent to the aromatic ring. The interplanar angle is 33.38 (3)°. Molecules are connected in chains parallel to [110] by classical hydrogen bonds of the N—H⋯O type from the other NH group to the benzoate C=O of a neighboring molecule.

Nanoparticles and nanocrystals of a new bidentate nickel(II) complex of N-[ethyl(propan-2-yl)carbamothioyl]-4-nitrobenzamide: synthesis, characterization, and crystal structures

The nickel(II) complex of N-[ethyl(propan-2-yl)carbamothioyl]-4-nitrobenzamide has been synthesized and characterized by Fourier transform-infrared spectroscopy, elemental analysis, nuclear magnetic resonance spectroscopy, and mass spectrometry (atmospheric pressure chemical ionization mass spectrometry). The single-crystal X-ray structures of N-[ethyl(propan-2-yl)carbamothioyl]-4-nitrobenzamide (1) and bis[N-[ethyl(propan-2-yl)carbamothioyl]-4-nitrobenzamide]nickel(II) (2) have been determined from single-crystal X-ray diffraction data. Loss of the N–H proton resonance and the N–H stretching vibration and the shift of the νC=O and νC=S stretching vibrations confirm formation of the metal complex. These studies show that the metal complex is neutral in cis-configuration. The complex has been used as a single-source precursor for the deposition of nickel sulfide nanocrystals by thermolysis. The nickel sulfide nanocrystals were characterized by X-ray powder diffraction and transmission electron microscopy.

1-(Adamantan-1-ylcarbon-yl)-3-(2,6-difluoro-4-hy-droxy-phen-yl)thio-urea.

In the title molecule, C18H20F2N2O2S, the 2,6-difluoro-4-hydroxyphenyl ring and the carbonylthiourea group are each essentially planar, with maximum deviations of atoms from their mean planes of 0.0113 (14) and 0.1017 (15) Å, respectively; the dihedral angle between these two planes is 71.03 (6)°. An intramolecular N—H⋯O hydrogen bond occurs. In the crystal, N—H⋯O and O—H⋯S hydrogen bonds connect the molecules into chains running diagonally across the bc plane. C—H⋯S and C—H⋯F contacts are also observed.

N-(4-Bromo-phen-yl)-4-nitro-benzamide.

In the title compound, C13H9BrN2O3, the dihedral angle between the mean planes of the two benzene rings is 3.6 (7)°. The amide group is twisted by 28.1 (6) and 31.8 (3)° from the mean planes of the 4-bromophenyl and 4-nitrobenzene rings, respectively. The crystal packing features weak intermolecular N—H⋯O and C—H⋯O hydrogen bonds resulting in a three-dimensional network.