Synthesis, characterization and X-ray structure of an oxazine derivative

The 5,6-dihydro-6-methyl-2,3-diphenyl-2H-1,4-oxazine-2-ol compound (2) was prepared unambiguously by condensation of 1,2-diphenylethanone with 1-amino-2-propanol in the presence of glacial acetic acid. The product was characterized by FT-IR, 1HNMR, UV-Vis spectroscopy and X-ray crystallography. Quantum chemical calculations are used to the proposed mechanism.  KEY WORDS: 1,2-Diphenylethanone, 1-Amino-2-propanol, Oxazine  Bull. Chem. Soc. Ethiop. 2010, 24(2), 283-287

Two new zinc(II) acetates with 3- and 4-aminopyridine

The synthesis and characterization of two new zinc(II) coordination compounds with 3- and 4-aminopyridine are reported. They were obtained after adding a water solution of $Zn(CH_3COO)_2$ · $2H_2O$ or dissolving solid $Zn(CH_3COO)_2$ · $2H_2O$ in methanol solutions of 3- and 4-aminopyridine. The products were characterized structurally by single-crystal X-ray diffraction analysis. Colourless crystals of the compound synthesized by the reaction of $Zn(CH_3COO)_2$ · $2H_2O$ and 3-aminopyridine (3-apy), are built of trinuclear complex molecules with the formula $[Zn_3(O_2CCH_3)_6(3- apy)_2(H_2O)_2]$(1). The molecules consists of two terminal $Zn$ atoms, coordinated tetrahedrally, and one central $Zn$ atom, coordinated octahedrally. Colourless crystals, obtained by the reaction of $Zn(CH_3COO)_2$ · $2H_2O$ with 4-aminopyridine (4-apy), consist of a mononuclear complex $[Zn(O_2CCH_3)_2(4-apy)_2]$(2). Hydrogen-bonding interactions in the crystal structures of both complexes are reported.Sintetizirali in karakterizirali smo novi cinkovi koordinacijski spojini s 3- in 4-aminopiridinom. Dobili smo ju z dodajanjem metanolne raztopine $Zn(CH_3COO)_2$ · $2H_2O$ v vodno raztopino 3-aminopiridina oziroma raztapljanjem $Zn(CH_3COO)_2$ · $2H_2O$ v metanolni raztopini 4-aminopiridina. Produkta sta bila okarakterizirana z rentgensko strukturno analizo monokristalov. Brezbarvni kristali, pridobljeni z reakcijo med $Zn(CH_3COO)_2$ · $2H_2O$ in 3-aminopiridinom, so zgrajeni iz trijedrnih koordinacijskih molekul s kemijsko formulo $[Zn_3(O_2CCH_3)_6(3-apy)_2(H_2O)_2]$(1). Molekula je sestavljena iz dveh terminalnih cinkovih ionov, ki sta tetraedično koordinirana, in enega centralnega iona, ki je oktaedrično koordiniran. Brezbarvni kristali, dobljeni z reakcijo med $Zn(CH_3COO)_2$ · $2H2_O$ in 4-aminopiridinom, sestojijo iz enojedrnih koordinacijskih molekul s kemijsko formulo $[Zn(O_2CCH_3)_2(4-apy)_2]$(2). Poročamo tudi o vodikovih vezeh v kristalnih strukturah obeh spojin

E-Notopterol

The title compound (systematic name: 4-{[(2E)-5-hydr­oxy-3,7-dimethylocta-2,6-dien-1-yl]­oxy}-7H-furo[3,2-g][1]benzopyran-7-one), C21H22O5, is a known furan­ocoumarin, which was isolated from the Chinese herbal product Radix seu Rhizoma Notopterygii. The crystal structure shows a weak O—H⋯O hydrogen bond

Optimized Synthesis of Tetrafluoroterephthalic Acid: A Versatile Linking Ligand for the Construction of New Coordination Polymers and Metal-Organic Frameworks

Pure 2,3,5,6-tetrafluoroterephthalic acid (H(2)tfBDC) is obtained in high yields (95%) by reacting 1,2,4,5-tetrafluorobenzene with a surplus (>2 equiv) of n-butyllithium in tetrahydrofuran (THF) and subsequent carbonation with CO2 without any extensive purification procedure. A single crystal X-ray structure analysis of H2tfBDC (1) confirms former data obtained for a deuterated sample (P (1) over bar, Z = 1). Recrystallization from water/acetone leads to single crystals of H(2)tfBDC center dot 2H(2)O (2, P2(1)/c, Z. 2), where an extensive hydrogen bonding network is found. By reacting H2tfBDC with an aqueous ammonia solution, single crystals of (NH4)(2)tfBDC (3, C2/m, Z. 2) are obtained. 3 is thermally stable up to 250 degrees C and shows an enhanced solubility in water compared to H(2)tfBDC. Monosubstituted 2,3,5,6-tetrafluorobenzoic acid (H(2)tfBC, 4) is obtained by reacting 1,2,4,5-tetrafluorobenzene with stoichiometric amounts (1 equiv) of n-butyllithium in THF. Its crystal structure (Fdd2, Z = 16) shows dimeric units as characteristic structural feature

Supplementary data for article: Peschel, L. M.; Holzer, C.; Mihajlovic-Lalic, L.; Belaj, F.; Mösch-Zanetti, N. C. Coordinative Flexibility of a Thiophenolate Oxazoline Ligand in Nickel(II), Palladium(II), and Platinum(II) Complexes. European Journal of Inorganic Chemistry 2015, 2015 (9), 1569–1578. https://doi.org/10.1002/ejic.201403108

Supporting information for: [https://doi.org/10.1002/ejic.201403108]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1677

Flow Technology for Telescoped Generation, Lithiation and Electrophilic (C3) Functionalization of Highly Strained 1-Azabicyclo[1.1.0]butanes

Strained compounds are privileged moieties in modern synthesis. In this context, 1-azabicyclo[1.1.0]butanes are appealing structural motifs that can be employed as click reagents or precursors to azetidines. We herein report the first telescoped continuous flow protocol for the generation, lithiation, and electrophilic trapping of 1-azabicyclo[1.1.0]butanes. The flow method allows for exquisite control of the reaction parameters, and the process operates at higher temperatures and safer conditions with respect to batch mode. The efficiency of this intramolecular cyclization/C3-lithiation/electrophilic quenching flow sequence is documented with more than 20 examples

Supplementary data for article: Peschel, L. M.; Holzer, C.; Mihajlovic-Lalic, L.; Belaj, F.; Mösch-Zanetti, N. C. Coordinative Flexibility of a Thiophenolate Oxazoline Ligand in Nickel(II), Palladium(II), and Platinum(II) Complexes. European Journal of Inorganic Chemistry 2015, 2015 (9), 1569–1578. https://doi.org/10.1002/ejic.201403108

Supporting information for: [https://doi.org/10.1002/ejic.201403108]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1677

Oxorhenium(V) complexes with N,O ligands – synthesis and biological studies

Rhenium complexes merit particular attention in the area of metallodrug design due to rhenium’s broad spectrum of oxidation states and consequently, the possibility to design compounds of great structural diversity [1,2]. Thus, the synthesis, chemical characterization, and antitumor activity in vitro of the six Re(V) complexes are described. Novel compounds were obtained via reaction of [ReOCl3(PPh3)2] with corresponding ligands (pyridine-2- carboxylic acid, 3-methylpyridine-2-carboxylic acid, 6-methylpyridine-2-carboxylic acid, 2,3- pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, and 2,6-pyridinedicarboxylic acid) in acetonitrile or dichloromethane/methanol at 78 °C for 3h. The complexes were fully characterized using NMR, IR, MS, and elemental analysis. Results of X-ray diffraction analysis for three of these compounds confirmed the proposed octahedral geometry with bidentate coordinated ligands, via both oxygen and nitrogen atoms. The antiproliferative effect was determined by MTT assay. All complexes expressed moderate to low cytotoxic potential. Complex with pyridine-2-carboxylic acid showed dose-dependent cytotoxic potential, particularly toward triple-negative breast adenocarcinoma cells MDA-MB-231 and pancreatic adenocarcinoma cells PANC-1. Drug combination studies in PANC-1 cells with that complex and Verapamil hydrochloride (VRP) showed a slight arrest of the cell cycle in the S phase and also increase its antiproliferative potential

Oxorhenium(V) complexes in the drug combination study

Rhenium complexes merit particular attention in the area of metallodrug design due to rhenium’s broad spectrum of oxidation states and consequently, the possibility to design compounds of a great structural diversity. Thus, the synthesis, chemical characterization and antitumor activity in vitro of the three Re(V) complexes is described. Novel compounds were obtained via reaction of [ReOCl3(PPh3)2] with corresponding ligands (pyridine-2-carboxylic acid, 3-methylpyridine-2-carboxylic acid and 6-methylpyridine-2-carboxylic acid) in acetonitrile at 78 °C for 3h. The complexes were fully characterized using NMR, IR, MS and elemental analysis. Their octahedral geometry with bidentate NO ligand was confirmed by X-ray diffraction analysis. Antiproliferative effect was determined by MTT assay and only the complex with pyridine-2-carboxylic acid (1) showed dose-dependent cytotoxic potential, particularly toward triple-negative breast adenocarcinoma cells MDA-MB-231 with IC50 68.90 ± 1.73 µM and pancreatic adenocarcinoma cells PANC-1 with IC50 69.8 ± 2.3 µM. Drug combination studies in PANC-1 cells with 1 and Verapamil hydrochloride (VRP) showed slight arrest of cell cycle in the S phase and also it increase its antiproliferative potential to IC50 51.4 ± 2.8 μM. Part of the research included a depletion of the glutathione (GSH) level by L-buthionine-sulfoximine (L-BSO) at sub-toxic concentrations (100 μM) in PANC-1 cells which caused an increase of activity of 1 to the IC50 57.67 ± 6.51 μM