Tris[(1‐methylimidazol‐2‐yl)methyl]amine–boric acid (1/1)

Cocrystallization of a poly­imidazole compound with boric acid results in the formation of the title compound, C₁₅H₂₁N₇·B(OH)₃, which has an extensive hydrogen‐bonding network. The O?N(im) separations (im is imidazole) range from 2.6991 (15) to 2.7914 (14) Å, with O—H?N angles ranging from 170.6 (18) to 175 (2)°. In addition, symmetry‐related boric acid mol­ecules form intermolecular hydrogen bonds, with an O?O distance of 2.7582 (14) Å, and symmetry‐related imidazole groups form π–π stacks, with a centroid‐to‐centroid separation of 3.533 Å.     

1,3‐Dimethyl‐2‐oxo‐4,6‐diphenyl‐1,2,3,4‐tetrahydropyridine‐3‐carbonitrile

The crystal structure of the title compound, C₂₀H₁₈N₂O, reveals a distorted half‐chair conformation of the central tetra­hydro­pyridine (THP) ring, with the cyano‐ and adjacent phenyl‐substituted C atoms displaced by 0.329 (1) and ?0.315 (1) Å, respectively, from the THP best plane. Steric interactions force the phenyl rings out of the THP plane by 49.21 (9) and 65.76 (5)°. The cyano moiety is coplanar with the THP plane.     

Synthesis of poly[(2‐oxo‐1,3‐dioxolane‐ 4‐yl)methyl methacrylate‐co‐styrene] by addition reaction of carbon dioxide and its compatibility with poly(methyl methacrylate) or poly(vinyl chloride)

We investigated the chemical fixation of carbon dioxide (CO ₂) to a copolymer bearing epoxide and the application of the cyclic carbonate group containing copolymer to polymer blends. In the synthesis of poly[(2‐oxo‐1,3‐dioxolane‐4‐yl)methyl methacrylate‐co‐styrene] [poly(DOMA‐co‐St)] from the addition of CO ₂ to poly(glycidyl methacrylate‐co‐styrene) [poly(GMA‐co‐St)], quaternary ammonium salts showed good catalytic activity at mild reaction conditions. The CO ₂ addition reaction followed pseudo first‐order kinetics with the concentration of poly(GMA‐co‐St). In order to expand the applications of the CO ₂ fixed copolymer, polymer blends of this copolymer with poly(methyl methacrylate) (PMMA) or poly(vinyl chloride) (PVC) were cast from N,N′‐dimethylformamide (DMF) solution. Miscibility of blends of poly(DOMA‐co‐St) with PMMA or PVC have been investigated both by differential scanning calorimetry (DSC) and visual inspection of the blends, and the blends were miscible over the whole composition ranges. The miscibility behaviors were also discussed in terms of FT‐IR spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

4,6‐Dimethyl‐2‐[(4‐phenylpiperidin‐1‐yl)methyl]isothiazolo[5,4‐b]pyridin‐3(2H)‐one and 4,6‐dimethyl‐2‐[(4‐phenyl‐1,2,3,6‐tetrahydropyridin‐1‐yl)methyl]isothiazolo[5,4‐b]pyridin‐3(2H)‐one

In the crystal structures of the title compounds, C₂₀H₂₃N₃OS, (II), and C₂₀H₂₁N₃OS, (III), significant differences occur in the conformation of, respectively, the phenylpiperidine and phenyltetrahydropyridine substituents at the 2‐position of the isothiazolopyridine system. The piperidine ring adopts a chair conformation, while the tetrahydropyridine ring assumes a half‐chair form. The phenylpiperidine and phenyltetrahydropyridine fragments exhibit different conformations resulting from the steric and conjugation effects in the phenyl ring, respectively. Theoretical calculations show that both conformations are energetically stable and correspond to a minimum of energy for the analyzed systems. The molecular packing in (II) is influenced by π–π interactions of the isothiazolopyridine systems, with a shortest centroid‐to‐centroid separation of 3.5843 (11) Å between pyridine rings. In the crystal structure of (III), the molecules are linked by C—H...O hydrogen bonds and C—H...π interactions.     

4,6‐Dimethyl‐2‐(3‐pyrid­yl)quinolin‐5‐amine

The title compound, C₁₆H₁₅N₃, shows a hindrance effect between adjacent amino and methyl groups that leads to a structural distortion, which is reflected in the non‐planarity of the quinoline entity and in the bond angles and distances. The crystal packing consists of chains along the b axis sustained by an inter­molecular hydrogen bond between the amino group and the N atom of the pyridyl ring.     

Synthesis and antimicrobial activity of novel 2‐(aryl)‐3‐[5‐(2‐oxo‐2H‐3‐chromenyl)‐1,3‐oxazol‐2‐yl]‐1,3‐thiazolan‐4‐ones

A series of novel 2‐(aryl)‐3‐[5‐(2‐oxo‐2H‐3‐chromenyl)‐1,3‐oxazol‐2‐yl]‐1,3‐thiazolan‐4‐ones 4a , 4b , 4c , 4e , 4f , 4g , 4h , 4i , 4j have been synthesized and assayed for their antibacterial activity against Gram‐positive bacteria viz. Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p), Micrococcus luteus (IFC 12708), and Gram‐negative bacteria viz. Proteus vulgaris (ATCC 3851), Salmonella typhimurium (ATCC 14028), Escherichia coli (ATCC 25922), and also antifungal activity against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), and Trichophyton mentagrophytes (IFO 40996). Among the screened compounds, 4d , 4e , 4f , 4g , and 4j exhibited potent inhibitory activity compared with the standard drug at the tested concentrations. The results reveal that, the presence of difluorophenyl in 4f and pipernyl ring in 4j at 2‐position of thiazolidine‐4‐one ring show significant inhibitory activity. The other compounds also showed appreciable activity against the test bacteria and fungi and emerged as potential molecules for further development. J. Heterocyclic Chem., 2011.     

2‐(1,3‐Dithian‐2‐yl)benzaldehyde and N‐{2‐[2‐(1,3‐dioxan‐2‐yl)phenoxy]­ethyl}phthalimide

The crystal structures of two elaborated‐porphyrin precursors have been determined. In the crystalline state, 2‐(1,3‐di­thian‐2‐yl)­benz­aldehyde, C₁₁H₁₂OS₂, has its di­thiane ring in a slightly distorted chair conformation. The mol­ecules pack in anti‐parallel chains. N‐{2‐[2‐(1,3‐Dioxan‐2‐yl)­phenoxy]­ethyl}­phthal­imide, C₂₀H₁₉NO₅, is in a folded conformation. The dihedral angle between the phthal­imide and phenyl planes is 80.07 (3)°. In the crystalline states, mol­ecules stack on top of one another.     

A helical zinc(II) coordination polymer assembled from 1,3‐bis[(pyridin‐3‐yl)methoxy]benzene and benzene‐1,4‐dicarboxylic acid

In catena‐poly[[aqua[1,3‐bis(pyridine‐3‐ylmethoxy)benzene‐κN]zinc(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O¹:O⁴], [Zn(C₈H₄O₄)(C₁₈H₁₆N₂O₂)(H₂O)]_n, each Zn^II centre is tetrahedrally coordinated by two O atoms of bridging carboxylate groups from two benzene‐1,4‐dicarboxylate anions (denoted L²⁻), one O atom from a water molecule and one N atom from a 1,3‐bis[(pyridin‐3‐yl)methoxy]benzene ligand (denoted bpmb). (Aqua)O—H...N hydrogen‐bonding interactions induce the formation of one‐dimensional helical [Zn(L)(bpmb)(H₂O)]_n chains which are interlinked through (aqua)O—H...O hydrogen‐bonding interactions, producing two‐dimensional corrugated sheets.     

Bis{tris[(1H‐benzimidazol‐3‐ium‐2‐yl)methyl]amine} tetraaquaocta‐μ2‐chlorido‐octachloridopentacadmate(II) monohydrate

The title compound, (C₂₄H₂₄N₇)₂[Cd₅Cl₁₆(H₂O)₄]·H₂O, contains a [Cd₅Cl₁₆(H₂O)₄]⁶⁻ anion, two triply protonated tris[(1H‐benzimidazol‐3‐ium‐2‐yl)methyl]amine cations and one solvent water molecule. The structure of the anion is a novel chloride‐bridged pentanuclear cluster. The five unique Cd^II centres have quite different coordination environments. Two of the central hexacoordinated Cd^II cations have a CdOCl₅ chromophore, in which each Cd^II cation is ligated by four bridging chloride ligands, one terminal chloride ligand and one water molecule, adopting a distorted octahedral environment. The third central Cd^II cation is octahedrally coordinated by four bridging chloride ligands and two water molecules. Finally, the two terminal Cd^II cations are pentacoordinated by two bridging and three terminal chloride ligands and adopt a trigonal–bipyramidal geometry. A three‐dimensional supramolecular network is formed through intra‐ and intermolecular O—H...O, O—H...Cl, N—H...Cl and N—H...O hydrogen bonds and π–π interactions between the cations and anions.<!?tpb=20.6pt>     

catena‐Poly[[[diaquazinc]‐bis{μ‐N2,N6‐bis[(pyridin‐3‐yl)methyl]pyridine‐2,6‐dicarboxamide}] dinitrate]

In the title compound, {[Zn(C₁₉H₁₇N₅O₂)₂(H₂O)₂](NO₃)₂}_n, the Zn^II cation is located at an inversion centre within a slightly distorted octahedron, ligated by four N atoms from four N²,N⁶‐bis[(pyridin‐3‐yl)methyl]pyridine‐2,6‐dicarboxamide (L) ligands occupying a plane about the Zn^II atom with the two water O atoms perpendicular to that. In the complex molecule, the bidentate bridging L ligands display helical R and S conformers, and link the Zn^II cations into a one‐dimensional centrosymmetric double‐chain structure containing 32‐membered rings. The nitrate anions reside in these rings and are involved in multiple N—H...O hydrogen‐bond interactions. On excitation at 390 nm, the title compound displays a strong blue emission centred at 449 nm. Investigation of the thermal stability shows that the network structure is stable up to 420 K.     

(4S)‐3‐[(2R,3S)‐3‐Hydr­oxy‐2‐methyl‐3‐phenyl­propion­yl]‐4‐isopropyl­oxazolidin‐2‐one

The mol­ecule of the title compound, C₁₆H₂₁NO₄, is chiral and has three asymmetric centres. The absolute configuration was not determined via diffraction measurements on the crystal, but was established from the known absolute configuration of the starting material. In the crystal structure, the mol­ecules assemble through inter­molecular hydrogen bonds into a macrostructure with helical channels.     

Chlorido­bis[(2‐oxoazocan‐1‐yl)methyl]­germanium(IV) trifluoro­methane­sulfonate

In the title compound, [Ge(C₈H₁₄NO)₂Cl]CF₃SO₃, which is the first complex containing an eight‐membered lactam (enantho­lactam) as ligand, the coordination polyhedron of the Ge^IV atom is inter­mediate between trigonal–bipyramidal and square‐pyramidal. Quantum chemical calculations of the crystal structure indicate the absence of additional coordination bonding between the Ge^IV atom and the trifluoro­methane­sulfonate anion.     

Synthesis of poly[(2‐oxo‐1,3‐dioxolane‐4‐yl) methyl methacrylate‐co‐ethyl acrylate] by incorporation of carbon dioxide into epoxide polymer and the miscibility behavior of its blends with poly(methyl methacrylate) or poly(vinyl chloride)

This study was related to the investigation of the chemical fixation of carbon dioxide to a copolymer bearing epoxide and the application of the cyclic carbonate group containing copolymer‐to‐polymer blends. In the synthesis of poly[(2‐oxo‐1,3‐dioxolane‐4‐yl) methyl methacrylate‐co‐ethyl acrylate] [poly(DOMA‐co‐EA)] from poly(glycidyl methacrylate‐co‐ethyl acrylate) [poly(GMA‐co‐EA)] and CO₂, quaternary ammonium salts showed good catalytic activity. The films of poly(DOMA‐co‐EA) with poly(methyl methacrylate) (PMMA) or poly(vinyl chloride) (PVC) blends were cast from N,N′‐dimethylformamide solution. The miscibility of the blends of poly(DOMA‐co‐EA) with PMMA or PVC have been investigated both by DSC and visual inspection of the blends. The optical clarity test and DSC analysis showed that poly(DOMA‐co‐EA) containing blends were miscible over the whole composition range. The miscibility behaviors were discussed in terms of Fourier transform infrared spectra and interaction parameters based on the binary interaction model. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1472–1480, 2001     

Piperidinium 3‐[(4‐hydroxy‐5,7‐di­methyl‐2‐oxo‐2H‐chromen‐3‐yl)­phenyl­methyl]‐5,7‐di­methyl‐2‐oxo‐2H‐chromen‐4‐olate

In the title salt, C₅H₁₂N⁺·C₂₉H₂₃O₆^?, both benzo­pyran systems are planar. Intermolecular N—H?O hydrogen bonds and a short O—H?O intramolecular hydrogen bond are observed in the structure.     

1‐[5‐(4,5‐Dimethyl‐1,3,2‐dioxaborolan‐2‐yl)thiophen‐2‐yl]ethanone and 4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)benzaldehyde

In both title compounds, C₁₀H₁₃BO₃S, (I), and C₁₃H₁₇BO₃, (II), the molecules adopt nearly planar conformations. The crystal packing of (I) consists of a supramolecular two‐dimensional network with a herringbone‐like topology formed by self assembly of centrosymmetric pairs of molecules linked via dipole–dipole interactions. The crystal structure of (II) consists of a supramolecular two‐dimensional network built up from centrosymmetric pairs of molecules viaπ–π interactions. These pairs of molecules are self‐organized in an offset fashion related by a symmetry centre, generating supramolecular ribbons running along the [101] direction. Neighbouring ribbons are stacked via complementary van der Waals and hydrophobic methyl–methyl interactions.     

Utility of 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile in heterocyclic synthesis

Pyrazolo[4,3‐d]pyrimidines, pyrazolo[4,3‐d]triazolino[4,3‐a]pyrimidines, 3‐(2‐thiazolyl)thiophenes, thiazolo[3,2‐a]pyridine and pyrazolo[1,5‐a]pyrimidines were synthesized from 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation and alternative synthesis route whenever possible.     

Antibacterial 4‐amino‐N‐(5‐methyl­isoxazol‐3‐yl)‐N‐[(4‐oxo‐2‐phenyl‐4H‐1‐benzopyran‐6‐yl)methyl]benzenesulfonamide

In the mol­ecule of the title compound, C₂₆H₂₁N₃O₅S, a new type of sulfonamide derivative with potential antibacterial activity, the flavone moiety is almost planar. The isoxazole and amino­phenyl rings are also planar and make dihedral angles of 77.0 (2) and 81.4 (1)°, respectively, with the best plane of the flavone ring system. The crystal structure is stabilized by intra‐ and inter­molecular hydrogen bonds.     

Reactivity of (2‐methylsulfanyl‐4‐oxo‐6‐phenyl‐4h‐pyrimidin‐3‐yl)‐acetic acid methyl ester towards hydrazine hydrate and benzylamine

The title ester 1 reacted with hydrazine hydrate to give hydrazide 2 , which underwent intramolecular cyclization to yield 1‐amino‐7‐phenyl‐1H‐imidazo[1,2‐a]pyrimidine‐2,5‐dione ( 3 ) or took place in a substitution reaction with benzylamine to form N‐benzyl‐2‐(2‐benzylamino‐4‐oxo‐6‐phenyl‐4H‐pyrimidin‐3‐yl)‐acetamide ( 4 ). The reaction of ester 1 with benzylamine gave corresponding amide 7 , disubstituted derivative 4 or 1‐benzyl‐7‐phenyl‐1H‐imidazo[1,2‐a]pyrimidine‐2,5‐dione ( 8 ) depending on the reaction conditions.     

[2‐(Imidazol‐4‐yl)ethylamine]{[2‐(imidazol‐4‐yl)ethyl][(1‐methylimidazol‐2‐yl)methyl]amine}copper(II) diperchlorate

In the title mononuclear complex, [Cu(C₅H₉N₃)(C₁₀H₁₅N₅)](ClO₄)₂, the Cu^II centre is surrounded by two N‐donor ligands, which impose a square‐pyramidal environment on the metal. The new tridentate ligand [2‐(imidazol‐4‐yl)­ethyl]­[(1‐methyl­imidazol‐2‐yl)­methyl]­amine (HISMIMA) lies in the basal plane, while the hist­amine ligand occupies the apical and one of the basal positions around the Cu^II ion.     

Synthesis of 1‐[(pyrazol‐3‐yl)methyl]pyridazin‐6‐ones

This paper presents the synthesis of 1‐[(pyrazol‐3‐yl)methyl]pyridazin‐6‐ones from ethyl 4‐(4,5‐dichloro‐6‐oxopyridazin‐1‐yl)‐3‐oxobutanoate.