SYNTHESIS AND ANTIOXIDANT EVALUATION OF 3-BROMO-FLAVONE

Objective: The objective of the study was to obtain a flavone derivative compound through N-bromosuccinimide (NBS) reducing the reaction. Theantioxidant activity of the synthetic compound was then assayed by the 2,2-diphenyl-1-picrylhydrazyl method.Methods: Chalcone (3 mmol) as intermediate precursor was suspended with dimethyl sulfoxide and reacted with NBS (3 mmol), stirred at roomtemperature for 25 min and diluted in cold water. The synthesis of flavone derivatives resulted in yellow crystalline powder, freely soluble in methanoland ethanol, renamed 60% with a melting point of 87.7°C. Detection by thin-layer chromatography using hexane:chloroform (2:1) showed single spotwith Rf = 0.38 which is different from the Rf value of the starting compound (chalcone, 0.66 and 0.78).Results: The results of the characterization of the synthesized compound using ultraviolet-visible and Fourier transform-infared showed the groupcharacteristic containing C=C (1604.77 and 1639.49 cm-1), C=O (1681.93 cm-1), C-O-C (1242.16 cm-1), Ar-H (3032.1 and 3062.96 cm-1), and C-Br(663.51 cm-1) at maximum absorption of wavelength 253 nm.Conclusion: The synthesis of flavone using NBS resulted in 3-bromo-flavone with a weak antioxidant activity.

Synthese, Kristallstruktur und spektroskopische Charakterisierung von Bis(dimethylammonium)hexachlorotitanat [Me2NH2]2[TiCl6]/ Synthesis, Crystal Structure, and Spectroscopic Characterization of Bis(dimethylammonium) Hexachlorotitanate [Me2NH2]2[TiCl6]

By the reaction of (Me3SiNH)2SiClNMe2 with TiCl4 the by-product [Me2NH2]2[TiCl6] was obtained in form of crystals suitable for single-crystal XRD (Pnnm, Z = 2, a = 722.01(3), b = 1428.36(5), c = 703.31(3) pm, T = 200 K, 901 independent reflections, 57 variables, R1 = 0.0636). The product was also synthesized in higher yield by the stoichiometric reaction of two equivalents of [Me2NH2]Cl with TiCl4 in CHCl3 at room temperature as a yellow crystalline powder. Bis(dimethylammonium) hexachlorotitanate is built up from [TiCl6]2- anions forming elongated octahedra and [Me2NH2]+ ions. The [TiCl6]2- ions are connected by the [Me2NH2]+ ions through N-H···Cl hydrogen bridges forming an arrangement which resembles that of an expanded rutile structure type. The elongation of the [TiCl6]2- octahedra was also verified by IR and Raman spectroscopy, confirming a local symmetry reduction from Oh to D4h. The solubility of [Me2NH2]2[TiCl6] in MeNO2 and MeCN was determined by means of 14N-NMR to be about 0.1 mol% and 0.3 mol%, respectively.