Facile synthesis of 3-substituted quinazoline-2,4-dione and 2,3-di-substituted quinazolinone derivatives

3-Substituted quinazoline-2,4(1H,3H)-dione and 2,3-di-substituted quinazolineone derivatives attract considerable interest due to their pharmacological properties. In this paper, we report the synthesis of N-substituted-3-nitrophthalimide derivatives II?CIII, the reactions of phthalimide III with amines, hydrazines, and amino acid derivatives to synthesise a small library of 3-substituted-5-nitroquinazoline-2,4(1H,3H)-diones IV?CXIV and 2,3-di-substituted-6-nitro-quinazolineones XVIII?CXIX.     

Crystal structure of tetrakisdiphenylammonium hexadecachlorotetrabismuthate(III)

[(C₆H₅)₂NH₂]₄ ⁺[Bi₄Cl₁₆]^4– crystallizes in the triclinic space group witha=11.835(2),b=12.393(2),c=12.625(3)Å, =108.37(3), =108.69(3), =96.00(3)° andD _c=2.135 g cm^–3 forZ=1. The [Bi₄Cl₁₆]^4– anion is a centrosymmetric cluster of four distorted edge-sharing BiCl₆ octahedra. The ranges of the Bi–Cl bonds are 2.484(4)–2.606(3)Å for Bi–Cl(terminal), 2.691(3)–2.956(4)Å for Bi-Cl(µ₂), and 2.960(3)–3.120(4)Å for Bi-Cl(µ₃). The cations and anions are held in place by weak hydrogen bonds.     

Copper perchlorate and tetrafluoridoborate compounds with the ligand 1,4,5-triazanaphthalene. Gradual transformation of mononuclear Cu(II) compounds via polynuclear mixed-valence Cu(II)/Cu(I) species to dinuclear Cu(I); syntheses, characterizations and X-ray structures

When the ligand 1,4,5-triazanaphthalene (abbreviated as tan) is reacted with Cu(II) BF(4)(-) and ClO(4)(-) salts, a variety of mononuclear compounds has been found, all with the [Cu(tan)(4)] unit and varying amounts of weakly coordinating axial ligands and lattice solvents. Reproducible compounds formed include two purple compounds, analyzing as [Cu(tan)(4)](ClO(4))(2)(CH(3)OH)(2)(H(2)O) (1) and [Cu(tan)(4)](BF(4))(2)(CH(3)OH)(1.5)(H(2)O) (3), and two blue compounds, analyzing as [Cu(tan)(4)](ClO(4))(2)(H(2)O)(2) (2) and [Cu(tan)(4)](2)(BF(4))(2)(H(2)O)(2) (4). Upon standing at room temperature, red-coloured, mixed-valence dinuclear-based 3D coordination polymers are formed by conversion of the purple/blue products, of which [Cu(2)(tan)(4)](n)(BF(4))(3n) (5) and the isomorphic methanol-water adduct [Cu(tan)(4)](n)(BF(4))(3n)(CH(3)OH)(n)(H(2)O)(5n) (5A) are presented in this paper. In addition a fully reduced dinuclear Cu(I) compound of formula [Cu(2)(tan)(3)(ClO(4))(2)] (7) has been observed, and structurally characterized, as a rare three-blade propeller structure, with a Cu-Cu distance of 2.504 ?.     

Synthesis,structural chemistry and antimicrobial activity of −(−) borneol derivative

Borneol is a monoterpene that is a part of traditional Chinese and Japanese medicine. (−) borneol reacted with methanesulfonyl chloride in THF/pyridine to afford the new 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate derivative in excellent yield. The product is characterized by H1NMR, C¹³NMR, mass spectroscopy as well as elemental analysis and its structure was identified by X-ray single crystal diffraction. The packing of 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methanesulfonate exhibits the non-classical C-H···O hydrogen bonding in C(4) and R² ₂(8) chain and ring motifs as structural determinants. This was also confirmed by the analysis of Hirshfeld surfaces. The 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate antimicrobial activity was tested and compared with its parent (−) borneol against three different pathogens. Particularly, 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate showed high sensitivity, compared to Chloramphenicol reference material, against Escherichia coli.      

Microwave irradiation: A facile,scalable and convenient method for synthesis of N-phthaloylamino acids

We describe herein a fast and rapid technique for preparation of N-phthaloyl amino acids under microwave irradiation. The microwave methodology is rapid, convenient, proceeds under mild conditions, and gives a better yield (81–98%) and high purity of the title compounds. The spectral data as well as the X-ray analysis established the structure of the prepared N-protected amino acids.     

Synthesis and characterization of microstructured sheets of semiconducting Ca[TCNQ]2 via redox-driven solid-solid phase transformation of TCNQ microcrystals

Microstructured sheets of semiconducting Ca[TCNQ]₂ (TCNQ = 7,7,8,8-tetracyanoquinodimethane) have been synthesized via electrochemically driven (TCNQ)/Ca[TCNQ]₂ solid-solid phase transformation that occurs upon one-electron reduction of solid TCNQ, mechanically attached to an electrode surface, in the presence of an aqueous Ca²⁺ _(aq) electrolyte solution. Voltammetric probing of the electrochemically irreversible TCNQ/Ca[TCNQ]₂ interconversion revealed that it is highly dependent on scan rate and Ca²⁺ _(aq) electrolyte concentration. This voltammetric behavior, supported by double potential-step chronoamperometric evidence, clearly attests that formation of Ca[TCNQ]₂ takes place via a rate-determining nucleation/growth process, which involves ingress of Ca²⁺ _(aq) cations into the TCNQ^·? crystal lattice at the triple phase TCNQ/TCNQ^·? _(s)│GC_(s)│Ca²⁺ _(aq) electrolyte junction. The overall redox process associated with this chemically reversible solid-solid transformation can be described by the equation: TCNQ⁰ _(S)?+?2e^??+?Ca²⁺ _(aq) ? {Ca[TCNQ]₂}_(S). SEM characterization of the morphology of the generated Ca[TCNQ]₂ material showed the formation of microstructured sheets, which are substantially different from those of parent TCNQ crystals and the needle-shaped crystals of group I cations (M⁺?=?Li, Na, K, Rb, and Cs). The kinetic and thermodynamic implications of the ΔE _p and E _m values as a function of scan rate are discussed in terms of nucleation–growth and their relevance to those reported for the conceptually related group I cations and binary M[TCNQ]₂ (M²⁺?=?Mn, Fe, Co, and Ni)-based coordination polymers.     

Coordination chemistry of the ligand 7-aza-1-hydroxy-benzotriazole. Crystal structures and antimicrobial activity of the catena-poly-[μ-chlorido(μ-7-aza-1-oxy-κN:O-benzotriazolyl-κN)]cobalt(II)methanol coordination polymer and of a new polymorph of the free ligand 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol

Reaction of cobalt chloride and 7-aza-1-hydroxy-benzotriazole (HOazbt) in alcoholic solution results in formation of the polymeric compound [Co(C₅H₃N₄O)(CH₃OH)Cl]_n. The compound has been characterized by elemental analysis, IR spectroscopy, and its 3D structure was determined by X-ray diffraction. Also its antimicrobial activity was determined.     

Experimental and quantum chemical studies of the electronic absorption spectra of pyrimidine derivatives

The electronic absorption spectra of different pyrimidine derivatives have been measured experimentally and calculated theoretically by the PPP and CNDO/S methods. These pyrimidine derivatives are: 4,6-dichloro-pyrimidine (I), 4,6-dichloro, 5-amino-pyrimidine (II), 2,4,6-trichloro-pyrimidine (III), 4,6-dihxdroxy-pyrimidine (IV), 4,6-dihxdroxy-5-nitro-pyrimidine (V), 2,4-diamino-pyrimidine (VI), 2,4-diamino-6-hydroxy-pyrimidine (VII), 2,4-dihydroxy-5-carboxy-pyrimidine (VIII), 2,4-dimethyl-6-hydroxy-pyrimidine (IX), 5-nitro-uracil (X), and orotic acid (XI). The observed electronic spectral shifts are quantitatively analyzed in relation to different solute–solvent interaction mechanisms. The effects of solvent polarity and hydrogen bonding on the spectra are discussed in the light of theoretical predictions. This comparative analysis provides a reasonable picture of the solvent effects on the absorption spectral properties of pyrimidine nucleobases.     

Synthesis,DFT Calculations,Antiproliferative, Bactericidal Activity and Molecular Docking of Novel Mixed-Ligand Salen/8-Hydroxyquinoline Metal Complexes

Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2′-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, ¹H NMR, ¹³C NMR, UV–VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H₂O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H₂O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC₅₀ values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC₅₀ values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.