Fatma Aydin

N-(4-Nitrobenzoyl)-N′-(1,5-dimethyl-3-oxo-2-phenyl-1H-3(2H)-pyrazolyl)-thiourea hydrate: Synthesis, spectroscopic characterization, X-ray structure and DFT studies

The title molecule (C19H17N5O4S·H2O) was synthesized and characterized by IR-NMR spectroscopy, MS and single-crystal X-ray diffraction. The molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the compound in the ground state have been calculated by using the density functional theory (DFT) method with 6-31G(d) basis set, and compared with the experimental data. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies and 1H and 13C NMR chemical shift values show good agreement with experimental data. To determine conformational flexibility, the molecular energy profile of the title compound was obtained with respect to the selected torsion angle, which was varied from -180° to +180° in steps of 10°. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and thermodynamic properties of the compound were investigated by theoretical calculations.

Synthesis of 4-(4-(dimethylamino)phenyl)-5-acetyl-6-phenyl-3,4-dihydropyrimidin-2(1H)-thione

4-(4-(dimethylamino)phenyl)-5-acetyl-6-phenyl-3,4-dihydropyrimidin-2(1H)-thione was prepared from benzoxyacetone (1) (1.62 g, 10 mmol), N,N-dimethylaniline (2) (1.21 g, 10 mmol) and thiourea (3) (1.140 g, 15 mmol) in dichloromethane (15 mL) as solvent using KF/Al2O3 (5 g) as a catalysis.[...]

3-Carboxypyridinium trichloroacetatochromate (CPTCAC): as a mild and effective new reagent for the thiols to disulfides

A new chromium(VI) reagent, 3-carboxypyridinium trichloroacetatochromate (CPTCAC) was prepared by reacting 3-carboxypyridine (nicotinic acid) and trichloroacetic acid with CrO3 in water. This oxidising agent oxidised the thiols to disulfides selectivily and in very high yields.

Synthesis, spectroscopic and structural characterisation of two p-nitrobenzamide compounds: experimental and DFT study

The title molecules, N-(1,5-dimethyl-3-oxo-2-phenyl-1H-3-(2H)-pyrazolyl)4-nitrobenzamide (C18H16N4O4·H2O) (I) and 2,2-dimethyl-3-(4-nitrobenzoyl)-5-(phenylamino)-2,3-dihydro-1,3,4-thiyadiazole (C17H16N4O3S) (II), were prepared and characterised by 1H NMR, 13C NMR, infrared spectroscopy (IR) and structural X-ray diffraction (XRD) techniques. The molecular geometries, vibrational frequencies of the title compounds in the ground state have been calculated by using the density functional theory (DFT) method with 6-31G(d) basis set, and compared with the experimental data. The calculated results showed that the optimised geometries from the DFT method agree with the X-ray structures well for both compounds. Theoretical calculations of harmonic vibration frequencies are in good agreement with experimental results. To determine conformational flexibility, the molecular energy profiles of the title compounds were obtained. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and thermodynamic properties of the title compounds were investigated by theoretical calculations.

Synthesis, characterization, and crystal structure of bis[4-(3′-benzoyl)thiocarbamidophenyl]ether

The title compound, bis[4-(3′-benzoyl)thiocarbamidophenyl]ether, was synthesized by the reaction of benzoylisothiocyanate with 4,4′-diaminodiphenylether in aprotic solvent. The structure was determinated by means of elemental analysis and FT-IR, 1H-NMR, 13C-NMR and MS spectroscopic techniques. The crystal structure was characterized by X-ray syngle crystal analysis: orthorhombic, sp. gr. Pnna, Z = 4. In crystal packing, there are intramolecular hydrogen bond N-H⋯O generating S(6) motif, and intermolecular hydrogen bond N-H⋯S forming R22 (8) ring.

Potassium fluoride/alumina mediated simple synthesis of Hantzsch 1, 4-dihydropyridines

A general and practical technique to achieve synthesis of 1,4-dihydropyridines in excellent yields has been investigated using potassium fluoride/alumina (KF/Al2O3) as a solid base. The ammonia was obtained either from thermal decomposition of ammonium acetate or by passing ammonia gases in the form of bubbled through hetereogenous reaction medium using an apparatus.

1,3,1',3'-(Dinaphthalene-1,8-diyl)bisthiourea

A new bisthiourea compound, 1,3,1′,3′-(dinaphthalene-1,8-diyl)bisthiourea, was synthesized. Its structure was characterized by elemental analysis, FT-IR and 1H-, 13C-NMR and MS spectroscopic techniques. The compound was found to selectively recognize fluoride anions among other halides as demonstrated by means of UV-vis absorption spectroscopic date and the naked eye.

N,N′-Bis-(4-nitrophenylcarbamothioyl)phthalamide

A novel colorimetric receptor linked to two nitrophenylurea groups was synthesized in good yields, characterized and their chromogenic properties investigated towards various anions (F−, Cl−, Br−, I−, OH−, AcO−, H2PO4− and CN−) by UV-Vis techniques. The receptor, effectively and selectively, recognized and distinguished the biologically important F− from other anions such as Cl−, Br−, I− etc. in DMSO. This selectivity could be easily observed by the naked eye, indicating that receptor is potential colorimetric sensor for fluoride ion.

N,N’-Bis-(2,5-dimethyl-3-oxo-1-phenyl-2,3-dihydro-1H-pyrazol-4-yl)phthalamide

The title compound, N,N’-bis-(2,5-dimethyl-3-oxo-1-phenyl-2,3-dihydro-1H-pyrazol-4-yl)phthalamide has been synthesized by reactions of o-phthaloyl chloride with 4-amino-2,5-dimethyl-1-phenyl-3-oxo-1H-pyrazolone in acetonitrile. The structure of the new compound was characterized by FT-IR, 1H NMR, 13C NMR and mass spectroscopic techniques. Physical parameters of the compound such as melting point, solubility, λmax were examined.

N-((2,5-Dimethyl-3-oxo-1-phenyl-2,3-dihydro-1H-pyrazol-4- yl)carbamothioyl)isonicotinamide

A new heterocyclic compound, N-[(2,5-dimethyl-3-oxo-1-phenyl-2,3-dihydro-1H-pyrazol-4-yl)carbamothioyl]isonicotinamide, was synthesized from isonicotinoyl isothiocyanate and 4-aminoantipyrine in acetonitrile solution. The title compound was characterized by FT-IR, 1H NMR, 13C NMR and MS spectroscopic methods. Physical parameters of the compound were examinated.