Wittig rearrangement of 1-[(1E)-3-(Benzyloxy)prop-1-en-1-yl]adamantane

Wittig rearrangement of an allyl benzyl ether containing an adamantane fragment has been studied. 1-[(1E)-3-(Benzyloxy)prop-1-en-1-yl]adamantane reacts with butyllithium to give [2,3]- and [1,2]-rearrangement products. The [2,3]-rearrangement product is a mixture of threo and erythro diastereoisomers, the latter prevailing.     

Die Kristallstruktur des N,N′-Bis(trimethylsilyl)imidazoliumiodids [(Me3Si)2(C3H3N2)]+I−

Crystal Structure of N,N′-Bis(trimethylsilyl)-imidazoliumiodide [(Me₃Si)₂(C₃H₃N₂)]⁺I^? Me₃SiI forms with N-Trimethylsiylimidazole (NTMSI) a 1:1 compound which is stable at room temperature. Single crystals can be isolated from a solution of chloroform. The X-ray crystal structure investigation proves an ionic structure.     

Poly[[tetrachlorido{μ4‐tetrakis[(pyridin‐4‐yl)oxymethyl]methane‐κ4N:N′:N′′:N′′′}dizinc(II)] dimethylformamide tetrasolvate]

A novel metal–organic framework, {[Zn₂Cl₄(C₂₅H₂₄N₄O₄)]·4C₃H₇NO}_n, has been synthesized solvothermally by assembling the semi‐rigid tetrahedral ligand tetrakis[(pyridin‐4‐yl)oxymethyl]methane (tpom) and zinc nitrate in dimethylformamide (DMF). The crystal structure is noncentrosymmetric (P2₁c). Each Zn^II cation has a tetrahedral coordination environment (C₂ symmetry), which is formed by two chloride ligands and two pyridine N atoms from two tpom ligands. The tetrahedral tetradentate tpom linker has a quaternary C atom located on the crystallographic axis. This linker utilizes all the peripheral pyridine N atoms to connect four Zn^II cations, thereby forming a wave‐like two‐dimensional sheet along the c axis. The two‐dimensional layer can be topologically simplified as a typical uninodal 4‐connected sql/Shubnikov net, which is represented by the Schläfli symbol {4⁴,6²}. Adjacent layers are further packed into a three‐dimensional structure by C—H...Cl hydrogen bonds.     

Preparation of (2E)-3-(4'-Halophenyl)prop-2-enoyl Sulfachlorpyridazine Sodium Salts and Their Interaction with Bovine Serum Albumin by Fluorescence Spectroscopy

Three (2E)-3-(4'-halophenyl)prop-2-enoyl sulfachlorpyridazine sodium salts(XPSCA) were synthesized. Their chemical structures were confirmed by ¹H NMR and ¹³C NMR, electrospray ionization mass spectrometry (ESI-MS), and infrared(IR) spectroscopy. The interactions between XPSCA and bovine serum albumin(BSA) were investigated under imitated physiological condition by fluorescence quenching technique and UV-Vis absorption spectroscopy according to the Stern-Volmer equation. The results from the emission quenching at different temperatures indicate that the quenching mechanism of serum albumin by XPSCA was static quenching mechanism at low XPSCA concentrations or a combined quenching(static and dynamic) mechanism at higher XPSCA concentrations. At different temperatures, the binding constant and the binding sites of XPSCA with BSA were investigated, and the distances were evaluated according to Förster non-radiative resonance energy transfer theory. The thermodynamic parameters were calculated according to van't Hoff equation, which implies that both van der Waals interaction and hydrogen bond played major roles in stabilizing the XPSCA-BSA complexes, whereas hydrophobic interactions were secondary. Moreover, the conformational changes in BSA were analyzed by synchronous fluorescence spectra.     

Some reactions of 4-[(2′,3′-diphenyl-6′-methoxy-5′-benzofuranyl)-methylene]- and 4-[(2′,3′-diphenyl-5′-methoxy-6′-benzofuranyl)-methylene]-2-phenyloxazolin-5-one

2,3-Diphenyl-5-formyl-6-methoxybenzofuran was reacted with hippuric acid to give 4-[(2′,3′-diphenyl-6′-methoxy-5′-benzofuranyl)methylene]-2-phenyloxazolin-5-one. The above mentioned oxazolone yielded 2,3-diphenyl-6-methoxybenzofuranylacetic acid by reaction with hydrazine hydrate, nitrous acid, benzene followed by acid hydrolysis. The reactions of the oxazolone with hydroxylamine hydrochloride and primary or secondary amines were also investigated.     

Kobalt(III)-Komplexe von N,N, N′, N′-Tetrakis-(β-aminoäthyl)-äthylendiamin (= «penten»)

Several salts containing the cation Co(penten)³⁺, in which the hexamin «penten» (formula: page 625) acts as a sexadentate ligand, have been synthesized and characterized. Its optical antipodes have been separated in some of the salts (Fig. 4), and the rate of racemization studied. In strongly alkaline solution one of the 5 chelate rings slowly opens and Co(penten)OH²⁺ is produced (Fig. 1), to which a first proton can be attached at the terminal NH₂-group (→ Co(Hpenten)OH³⁺), and a second which converts the hydroxo-complex into the aquo-complex (→ Co(Hpenten)OH⁴⁺). The equilibria between Co(penten)³⁺, Co(penten)OH²⁺, Co(Hpenten)OH³⁺ and Co-(Hpenten)OH₂⁴⁺ have been elucidated, and the kinetics of the ring opening and ring closing reactions have been studied. Ring opening and ring closure take place with retention of configuration. It proved impossible to open two of the chelate rings of Co(penten)³⁺. Cristalline salts with cations of the general formula Co(penten)X³?λ or Co (Hpeten)X^4?λ, with Xλ? ? OH?, H₂O, F?, Cl?, Br?, J?, SCN?, NO₂,? and CO₃²?, have been obtained and characterized (Fig. 1, 2, 7 and Table 1).     

4-[3,5-Bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]- benzoic Acid: A Novel Efficient and Selective Iron(III) Complexing Agent

An exceptionally stable 1:2 complex [FeL₂]³⁻ is formed from the ligand H₃L and Fe^III. In contrast, the affinity of this ligand for other biometals is relatively small. These properties make H₃L a highly promising candidate for medical applications (e.g. for the treatment of iron overload).     

Regioselective Intermolecular Cyclization of Methyl (E)-3-[(4S,5S)-5-Acetyl-2,2-dimethyl-1,3-dioxolan-4-yl)]prop-2-enoate

Russian Journal of Organic Chemistry - Methyl (E)-3-[(4S,5S)-5-acetyl-2,2-dimethyl-1,3-dioxolan-4-yl)]prop-2-enoate obtained from D-ribose eliminates water on storage and transforms into a bicyclic...     

Studies on Antifungal Agents. Part 22. 3-aryl-5-[(aryloxy)alkyl]-3-[(1H-imidazol-1-yl)methyl]-2-methylisoxazolidines and related derivatives

The synthesis and antifungal activity of a novel series of 3-aryl-5-[(aryloxy)alkyl]-3-[(1H-imidazol-1-yl)-methyl]-2-methylisoxazolidines and related compounds, are discussed. The synthesis of the title compounds was accomplished via a 1,3-dipolar cycloaddition of α-substituted ketonitrones with l-alkenyl phenyl ethers (Scheme 2 and 3). The compounds were evaluated for in vitro antifungal activity in solid agar cultures against a broad variety of yeast and systemic mycoses and dermatophytes. While antifungal activity was evident throughout the series, in general, derivatives having halogen atom(s) in either or both aryl rings demonstrated the highest potency, especially against Trichophyton rubrum and Candida albicans. The dichloro analog 20 (PR 967-248) was found to possess the most useful activity. Its minimum inhibitory concentration (MIC) values ranged between 0.2 and 2.0 μg/ml, as compared to 0.2–20.0 μg/ml for the standard drug ketoconazole (4).     

N,N,N′,N′-Tetramethylethylendiamin-di(tert-butyl)aluminium-Kationen — Molekülstruktur des [(Me3C)2Al · TMEDA]⊕[(Me3C)2AlBr2]⊖

(N,N,N′,N′ -tetramethylethylendiamine) di(tert-butyl)aluminium Cations — Molecular Structure of [(Me₃C)₂Al(TMEDA)]^⊕[(Me₃C)₂AlBr₂]^? Dimeric di(tert-butyl)aluminium halides (Me₃C)₂AlX (X = Cl, Br) react with N,N,N′,N′ -tetramethylethylendiamine (TMEDA) to give three compounds: the salt-like [(Me₃C)₂Al(TMEDA)]^⊕[(Me₃C)₂AlX₂]^? 1 , characterized by crystal structure determination, and [(Me₃C)₂Al(TMEDA)]^⊕X^? 3 both with chelating amine, and the more covalent, pentane soluble (Me₃C)₂AlX(TMEDA) 2 with TMEDA bound by only one nitrogen atom. The reaction resembles the symmetrical and unsymmetrical cleavage of diborane(6). 3 (X = Cl) is also formed by treatment of 1 with boiling n-hexane in the presence of TMEDA over a period of 24 hours, while for X = Br the more covalent 2 is the main product under similar conditions. In solution 2 decomposes slowly yielding different products in dependency of the solvent: in benzene 3 and in n-pentane 1 are formed.     

Synthesis,Crystal Structure and Anti-integrase Activity of 25,27-Bis[(Z)-4-(p-methoxyphenyl)-4-hydroxybut-3-en-2-one-1-methyl]-26,28-dihydroxycalix [4] arene

The title compound(C50H44O10) was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/c with a = 16.713(4), b = 13.189(3), c = 19.434(5) , β = 104.411(4)°, Mr = 804.85, Dc = 1.288 g/cm3, V = 4149.2(17) 3, Z = 4, F(000) = 1696, μ(MoKa) = 0.089 mm-1, T = 296(2) K, 7279 independent reflections with 3172 observed ones(I 2σ(I)), R = 0.0520 and wR = 0.1203 with GOF = 0.928(R = 0.1464 and wR = 0.1657 for all data). The calixarene moiety maintains the symmetric cone conformation through intramolecular O–H···O hydrogen bonds. Preliminary bioassays indicated that the title compound has a potent inhibitory activity against the strand transfer process of HIV-1 integrase.