Molbank — Open Access Journal

An amide chalconehas been synthesized in a two-step reaction. First, N-(4-acetylphenyl)quinoline-3-carboxamide 2 was synthesized by the reaction of quinoline-3-carboxylic acid 1 and thionyl chloride (SOCl₂), following the addition of 4-aminoacetophenone. Then, a typical Claisen–Schmidtreactionwas made between 2 and piperonal using KOH solution as a catalystin ethanol, under ultrasonic irradiation. The structure of the target compound was established by FTIR (Fourier-transform infrared spectroscopy), HRMS, ¹H and ¹³C-NMR. Full article

A cyclam (1,4,8,11-tetraazacyclotetradecane)-based macrocycle bearing two benzyl and two 2-hydroxy-3,5-di-tert-butylbenzyl pendent arms was synthesized and characterized using spectroscopic techniques and single crystal X-ray diffraction. The macrocycle crystallizes in the triclinic space group P-1, with the asymmetric unit containing one-half of the molecule. The structure is stabilized by hydrogen-bonding which exists between the phenolic protons and the nitrogen atoms of the macrocyclic ring. The presence of this hydrogen bonding is observed in the ¹H-NMR due to the deshielded nature of the phenolic OH peak (δ 9.99). Cyclic voltammetry of the ligand revealed a single quasi-reversible peak at −0.58 V (E_pc = −0.48 V and E_pa = −0.68 V), which is due to the electrochemical oxidation of the phenol to the phenoxyl radical. Full article

A new chloroform adduct of the N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene (SIPr) has been prepared via C–H bond activation of the chloroform at the carbene carbon. This redox product was crystallized and was characterized by ¹H and ¹³C-NMR spectroscopy, elemental analysis (EA), and single-crystal X-ray diffraction. The ¹H and ¹³C-NMR spectroscopic data are in agreement with the crystal structure. Density functional theory (DFT) calculations were performed as a means for comparison to experimental data and the computational results are in agreement with those obtained experimentally. Full article

A new pyranocoumarin, namely 5,9,11-trihydroxy-10-(2″-hydroxy-3″-methylbut- 3″en-1-yl)-2,2-dimethyl-3-(2′-methylbut-3′-en-2′-yl)-2H,12H-pyrano[2,3-a]xanthen-12-one 1, was isolated from the stem barkof Calophyllum pesudomole. The structure of compound 1was elucidated based on its ultaraviolet (UV); infrared (IR); high resolution electro spray ionization mass spectrometry (HRESIMS); 1D and 2D nuclear magnetic resonance (NMR) spectral data. Full article

The title compound, methyl N-[1-(benzoylamino)-2-methoxy-2-oxoethyl]tryptophanate 2, was synthesized in high yield, via N-alkylation reaction of methyl 2-azido-2-benzamidoacetate with methyl 2-amino-3-(1H-indol-3-yl)propanoate in acetone, with the presence of diisopropylethylamine as a base. The structure of the prepared compound was characterized by ¹H, ¹³C NMR in addition to MS, X-Ray diffraction data, and elemental analysis. This compound was tested in vitro for its antibacterial activity against Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, and Gram-negative bacteria, Escherichia coli,Pseudomonas aeruginosa, and Salmonella enteric. The MIC values showed that the synthesized compound had a bactericidal effect against the strains tested. Full article

The single crystal structure of bis(2,4,6-trimethylphenyl)phosphine oxide has been determined. All interatomic distances and angles can be considered normal. The aryl substituents adopt an intermediate configuration when compared to both sterically unhindered (e.g., diphenylphosphine oxide) and congested (e.g., bis(2,4,6-tri-tert-butylphenyl)phosphine oxide) secondary phosphine oxides, illustrating the influence of steric congestion on the molecular structure. Full article

The title ester (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl 4-aminobutyrate hydrochloride was obtained in 96% yield via Steglich esterification. The structure of the target compound was established by FTIR, HR-MS, ¹H-NMR, ¹³C-NMR spectral analysis, and single crystal X-ray diffraction study. Single crystals of the title ester suitable for X-ray investigation were obtained by slow evaporation of the methanolic solution at room temperature. The purity of compound was assessed using HPLC coupled to mass spectrometry. Full article

An interaction of water-methanol solution of sodium1,4-benzenediacetate (bda) and 4,4′-bipyridylethelene (bpee) with aqueous solution of Zn(NO₃)₂·6H₂O at room temperature yielded colourless crystals of 1 after three weeks in a sealed glass tube. The compound with composition C₂₂H₁₈ZnN₂O₄ crystallizes in monoclinic space group P2₁/c, with the following cell dimensions: a = 10.4566(2), b = 13.3085(2), c = 13.7189(2) Å, β = 101.491(1)°. In the structure of 1, two Zn(II) neighbours are connected by two bda ligands adopting chelating and bidentate-bridging coordination modes to form a dimeric unit (Zn₂O₈N₄) with the Zn–Zn distance of 4.0432(6) Å. The carboxyl-bridged dimeric units are extended along the [001] direction by bpee co-ligands and further linked by bda ligand to form a three-dimensional network structure. The IR shows the characteristic bands of the carboxylates at 1611/1507 cm⁻¹ and 1424/1373 cm⁻¹, respectively, for asymmetric and symmetric stretching −CO₂⁻ vibrations. The separation ∆[ν_asym(CO₂⁻) − ν_sym(CO₂⁻)] values of 187 and 134 cm⁻¹ are indicative of chelating and bidentate bridging coordination modes of the carboxylate to the metal centre. Full article

This note describes a sequence converting an oxime-substituted pyrrolidine into a trisubstituted pyrrole structure. The synthetic route is based on a double chlorination of the pyrrolidine substrate followed by the base induced formation of both an imine and a nitrile oxide functionality. The latter reacts with an immobilized thiourea to yield an isothiocyanate which upon elimination generates the final pyrrole in an unprecedented cascade of events. Full article

A novel di-Mannich derivative of curcumin pyrazole, 2-[(2,6-dimethyl morpholin-4-yl)methyl]-4-[(E)-2-{3-[(E)-2-{3-[(2,6-dimethylmorpholin-4-yl)methyl]-4-hydroxy-5-methoxyphenyl}ethenyl]-1H-pyrazol-5-yl}ethenyl]-6-methoxyphenol (2), has been synthesized through a Mannich reaction of curcumin pyrazole (1), formaldehyde, and 2,6-dimethylmorpholine. The structure of the synthesized compound was confirmed on the basis of FTIR, ¹H-NMR, ¹³C-NMR, 2D Heteronuclear Single-Quantum Correlation (HSQC) and 2D Heteronuclear Multiple Bond Correlation (HMBC), and mass spectral data. The water solubility was evaluated and the result showed that compound 2 was three times more soluble than that of curcumin pyrazole (1) and curcumin. Full article

A dicarbonylruthenium(II) complex containing bidentate 2-(2-pyridyl)-1,8-naphthyridine, as well as monodentate aqua and chlorido ligands, were isolated and characterized using spectroscopic techniques and single crystal X-ray diffraction. These data indicate that geometrical isomerization occurs during the substitution reaction involving a superacid. Density functional theory (DFT) calculations were performed on the plausible geometrical isomers. The DFT-optimized structures and calculated infrared spectra suggest that the experimentally obtained structure is stable. Full article

This note describes a novel reaction cascade in which a tosylhydrazone derivative of eucarvone undergoes a non-classical dimerization process under basic conditions. The key step in this sequence is a dipolar cycloaddition between a diazo species and a transient cyclopropene. A proposed mechanism for this sequence is presented that is supported by single crystal X-ray analysis of the resulting dimer. We believe this unique transformation is of note as it highlights a neat and efficient entry to complex polycyclic architectures containing an embedded pyrazoline moiety. Full article

1,2,3,4-Tetra-O-acetyl-β-d-mannuronic acid was synthesized in three steps from commercial d-mannose in 21% yield. Regioselective 6-O-tritylation followed by per-acetylation and 6-OTr removal using HBr/AcOH gave the required primary alcohol substrate, which was then oxidised to the target compound using TEMPO/BAIB. None of the synthetic steps required column chromatography and the product was fully characterized by ¹H-NMR, ¹³C-NMR, 2D NMR, MS and IR. Full article

Ethyl 2-[2-(4-nitrobenzoyl)-1H-indol-3-yl]acetate was prepared in good yield and characterized by the aza-alkylation/intramolecular Michael cascade reaction of (E)-ethyl 3-[2-(tosylamino)phenyl]acrylate with 2-bromo-4′′-nitroacetophenone, followed by desulfonative dehydrogenation with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) The structure of the newly synthesized compound was determined using ¹H-,¹³C-NMR, IR and mass spectral data. Full article

A new compound belonging to the “heterostilbene” derivative, namely ethyl (E)-4-(2,4-dimethoxyphenyl)-6-(2,4-dimethoxystyryl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (2), has been successfully synthesized as an unprecedented side product of the Biginelli reaction between 2,4-dimethoxybenzaldehyde, ethyl acetoacetate and urea, employing PTSA as catalyst in reflux conditions and using ethanol as solvent. The molecular structure of compound (2) was established by FTIR, HRESIMS, 1D and 2D NMR. Full article

The alkylation of 1,1,2-trimethyl-1H-benzo[e]indole with 2-chloroacetamide, followed by work-up of the reaction mixture with a base and the subsequent treatment of a crude product with acetic acid gives 10a,11,11-trimethyl-10a,11-dihydro-8H-benzo[e]imidazo[1,2-a]indol-9(10H)-one. The structure assignments were based on data from ¹H, ¹³C, and ¹⁵N-NMR spectroscopy. The optical properties of the obtained compound were studied by UV–Vis and fluorescence spectroscopy. Full article