Molbank — Open Access Journal

On the basis of the knowledge from traditional herbal and folk medicine, flavonoids are among the most studied chemical classes of natural compounds for their potential activity as phosphodiesterase 5 (PDE5) inhibitors. We here describe the preparation of a semi-synthetic hydrazone derivative of quercetin, 2-(3,4-dihydroxyphenyl)-4-(2-(4-nitrophenyl)hydrazono)-4H-chromene-3,5,7-triol, that was obtained via a single-step modification of the natural compound. The product was characterized by NMR, mass spectrometry and HPLC. Preliminary molecular modeling studies suggest that this compound could efficiently interact with PDE5. Full article

6-Hydroxy-2-methylbenzofuran-4-carboxylic acid was synthesized in two steps, starting from 3,5-dihydroxybenzoate. The product was obtained through a direct thermal one-pot cyclization with propargyl bromide, followed by a base-catalyzed hydrolysis. Its molecular structure was elucidated by means of mono- and bidimensional NMR techniques, ESI-MS, FT-IR and single-crystal X-ray diffraction. Full article

In the field of homogeneous catalysis, particularly in anti-Markovnikov hydration, sterically demanding phosphine ligand has found to be very effective. Here we report the crystal structure of a phosphine-imidazolium salt which crystallized in monoclinic space group P_21/c with a = 16.6623(13) (Å), b = 10.6686(8) (Å) and c = 12.8916(11) with = 110.232(2). Hirshfeld surface analysis show that the halogen–hydrogen interaction leads to a formation of 1D chain. Full article

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by ¹H and ¹³C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring. Full article

G-quadruplex DNA is the target of several natural and synthetic small molecules with antiproliferative and antiviral activity. We here report the synthesis through Sonogashira reaction and A3 coupling of a disubstituted anthracene derivative, 9,10-bis[(4-(2-hydroxyethyl)piperazine-1-yl)prop-2-yne-1-yl]anthracene. The binding of this compound to G-quadruplex and double stranded DNA sequences was evaluated using electrospray ionization mass spectrometry (ESI-MS), demonstrating selectivity for the first structure. The interaction pattern of the ligand with G-quadruplex was investigated by molecular docking and stacking was found to be the preferred binding mode. Full article

Imidazolines are a valuable class of organic compounds, namely ligands of imidazoline receptors, chiral ligands for metal catalysis, synthetic intermediates. The title compound has been prepared through a modified procedure, employing N-benzylethylenediamine and thiophene-2-carbaldehyde under the action of N-bromosuccinimide (NBS) in dichloromethane (DCM) in a good 78% yield. Full article

A new hybrid compound, 4-(3-phenyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)thieno[3,2-d]pyrimidine 3, with promising biological activity was efficiently synthesized by the reaction of 3-phenyl-1-(thieno[3,2-d]pyrimidin-4-yl)-1H-pyrazol-5-amine with Vilsmeier–Haack reagent and subsequent treatment with ammonium carbonate. The structure of the synthesized compound was fully characterized by ¹H-, ¹³C-NMR, IR spectroscopy, mass-spectrometry and elemental analysis. Full article

In this communication, the electrochemically induced multicomponent transformation of 3-methylbenzaldehyde, 3-(4-bromophenyl)isoxazol-5(4H)-one and kojic acid in n-PrOH in an undivided cell in the presence of sodium bromide was carefully investigated to give 3-(4-bromophenyl)-4-{[3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl](m-tolyl)methyl}isoxa- zol-5(2H)-one in good yield. The structure of the new compound was established by means of elemental analysis, mass-, nuclear magnetic resonance and infrared spectroscopy. Furthermore, its structure was determined and confirmed by X-ray analysis. The synthesized compound is a promising compound for different biomedical applications, and, in particular, for the regulation of inflammatory diseases, as shown by docking studies in this research. Full article

Afatinib is a 4-anilinoquinazoline tyrosine kinase inhibitor (TKI) in the form of a dimaleate salt which is indicated for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC). The most scalable route for the synthesis of this drug was reported in two Boehringer Ingelheim patents, in which the title compound, 4,7-dichloro-6-nitroquinazoline (IV), is an important intermediate. Compound IV is also present in a number of synthetic pathways for various 4,7-disubstituted quinazoline derivatives displaying high therapeutic potential. However, no detailed characterization of this popular compound has been reported, possibly due to its high instability. In this paper, IV was prepared in an overall yield of 56.1% by a 3-step process (condensation, nitration, and chlorination) from 2-amino-4-chlorobenzoic acid (I). The target compound has been for the first time fully characterized by melting point, mass-spectrometry, FT-IR, ¹H-NMR and ¹³C-NMR spectroscopies. Full article

In this short note communication, we report the synthesis of a novel amide 4’-methyl-2’-(quinolin-8-ylcarbamoyl)-biphenyl-4-carboxylic acid ethyl ester by the Ru-catalyzed C(sp²)-H bond arylation reaction. The catalytic C-H bond functionalization reaction was employed, amongst other reaction reagents and conditions, [RuCl₂(p-cymene)]₂ as a precatalyst and (p-tol)₃P as a ligand. The arylation product was characterized by various spectroscopic methods (¹H NMR, ¹³C NMR, IR, GC-MS, and IR spectroscopy), and its composition was confirmed by elemental analysis. Full article

We describe the synthesis of planar-chiral diferrocene compounds 4, 7 and 12, intended as key precursors for a new family of asymmetric catalyst ligands with less complex structures than their popular equivalents. In contrast to conventional 1,2-disubstituted ferrocenes containing center-chiral and planar-chiral elements, these compounds are purely planar-chiral due to the absence of α-substiuted ethyl groups. The title compounds 4, 7 and 12 were obtained from known precursors in 87%, 59% and 60% yields, respectively. Full article

4-Phenyl-1,8-naphthalimide was synthesized by imidation of commercially available 4-bromo-1,8-naphthalic anhydride, followed by Suzuki coupling with phenyl boronic acid, both under microwave heating. The microwave-assisted reactions were found to be faster and more efficient than reactions carried out by heating in oil-baths. While this compound was quite fluorescent in solvents such as chloroform, methanol and ethanol, it is virtually non-fluorescent in DMSO; however, upon the addition of water to DMSO solutions of this dye, fluorescence was restored, suggesting a tendency for aggregation-induced emission. The fluorescent properties of 4-phenyl-1,8-naphthalimide were found to be influenced by salt concentrations, likely as a result of hydrophobic effects. While this dye does not show binding to DNA, presence of bovine serum albumin leads to effective fluorescence quenching. Full article