New aspects of the nitration of some imidazo[1,2-a]pyridines. CNDO/2 calculations from X-ray structures

Jc, Teulade; Escale, R.; Rossi, Jc.; Jp, Chapat; Grassy, G.; Payard, M.

doi:10.1071/ch9821761

Cited by 17 publications

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“…The other angles and bond distances were similar to those of other methylene hydantoins recently reported . The bond lengths measured in the imidazopyridine system were consistent with those of other compounds in the same series 2 ORTEP drawing of 8a ; the sizes of H atoms have been reduced for clarity.…”

Section: Resultssupporting

confidence: 86%

Solid-Supported Heterocumulenes: Preparation and Crystal Structure of Azaaplysinopsins

et al. 1997

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Annulation of carbodiimides 6a,b, on alumina solid support, selectively gives (Z)-hydantoins 8a,b determined on the basis of X-ray analysis while thermal cyclization affords, after purification, 8a,b with imidazolones 10a,b. In the imidazopyrimidine series, thermal reaction of heterocumulenes 6d yields, via a Dimroth rearrangement, the dipyridoimidazolic compound 11. In all cases, mechanisms for the observed cyclizations have been proposed.

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Section: Resultssupporting

confidence: 86%

Solid-Supported Heterocumulenes: Preparation and Crystal Structure of Azaaplysinopsins

et al. 1997

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“…The optimized bond lengths and bond angles obtained in the most stable tautomer of ICPY (ICPY‐1) using the B3LYP functional with 6‐311++G(d,p), 6‐311G(d,p), 6‐31+G(d,p), and 6‐31G(d) basis sets are given in Table II; while the numbering system of the atoms for computation is plotted in Figure 2. The optimized geometry is compared with the structural parameters obtained from crystallographic analysis of similar molecules or units, benzimidazole 13, 5‐ethoxy‐1‐azaindolizine 34, and 5‐methyl‐1H‐imidazo[4,5‐b]pyridine 24, pyrrole 35, and indole 36. The conformation of the molecule is planar.…”

Section: Resultsmentioning

confidence: 99%

The effects of acrylate monomers and polystyrene addition on the morphology of DOP‐plasticized styrene–acrylate polymer particles prepared by SPG emulsification and suspension polymerization

Nuisin

Omi

Kiatkamjornwong

2005

J of Applied Polymer Sci

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ABSTRACT:Fairly uniform copolymer particles of methyl acrylate (MA), butyl acrylate (BA), or butyl methacrylate (BMA) were synthesized via Shirasu porous glass (SPG) membrane and followed by suspension polymerization. After a single-step SPG emulsification, the emulsion composed mainly of the monomers. Hydrophobic additives of dioctyl phthalate (DOP), polystyrene molecules, and an oil-soluble initiator, suspended in an aqueous phase containing poly-(vinyl alcohol) (PVA) stabilizer and sodium nitrite inhibitor (NaNO 2 ), were subsequently subjected to suspension polymerization. Two-phase copolymers with a soft phase and a hard phase were obtained. The composite particles of poly(St-co-MA)/PSt were prepared by varying the St/PSt ratios or the DOP amount. The addition of PSt induced a high viscosity at the dispersion phase. The molecular weight slightly increased with increasing St/PSt concentration. The multiple-phase separation of the St-rich phase and PMA domains, observed by transmission electron microscopy, was caused by composition drift because the MA reactivity ratio is greater than that of St. The addition of DOP revealed the greater compatibility between the hard-St and soft-MA moieties than that without DOP. The phase morphologies of poly(St-co-MA), poly(St-co-BMA), and their composites with PSt were revealed under the influence of DOP.

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“…1. The optimized geometry is reported in Table 1, together with the structural parameters obtained from crystallographic analysis for the similar molecule, 5-ethoxy-1-azaindolizine [25] and benzimidazole [26]. These studies show that pyridine and imidazole heterocycles are planar despite the presence of the bridgehead nitrogen atom N(6).…”

Section: Molecular Parametersmentioning

confidence: 99%

“…Figure 3 shows the normal coordinate displacements for some selected modes. These include modes 19,21,25,26,27,31, and 32 of A 0 symmetry, and 17 of A 00 symmetry. The vibrational motions are presented by the vector corresponding to the atomic displacement for each atom and computed wavenumbers.…”

Section: Vibrational Frequencies and Assignmentsmentioning

confidence: 99%

FT-IR spectra, vibrational assignments, and density functional calculations of imidazo[1,2-a]pyridine molecule and its Zn(II) halide complexes

Yurdakul

Badoğlu

2009

Struct Chem

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The geometry, frequency, and intensity of the vibrational bands of imidazo[1,2-a]pyridine (which is abbreviated as impy) were obtained by the density functional theory (DFT) calculations with BLYP, B3LYP, and B3PW91 functionals and 6-31G(d) basis set. The optimized geometric bond lengths and bond angles are in good agreement with the available X-ray data. The infrared spectrum of imidazo[1,2-a]pyridine was computed by the DFT method in order to reproduce the vibrational wavenumbers and intensities with an accuracy, which allows reliable vibrational assignments. Total energy distribution and isotopic shifts have been calculated in order to help for the perfect assignment of the vibrational modes. The zinc halide complexes Zn(impy) 2 X 2 [X = Cl, Br, and I] have also been synthesized. The compounds were characterized using the elemental analysis, FT-IR spectra, and quantum chemical calculations. The geometry optimization of Zn(impy) 2 X 2 yields distorted tetrahedral environment around Zn ion.

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New aspects of the nitration of some imidazo[1,2-a]pyridines. CNDO/2 calculations from X-ray structures

Cited by 17 publications

References 0 publications

Solid-Supported Heterocumulenes: Preparation and Crystal Structure of Azaaplysinopsins

Solid-Supported Heterocumulenes: Preparation and Crystal Structure of Azaaplysinopsins

The effects of acrylate monomers and polystyrene addition on the morphology of DOP‐plasticized styrene–acrylate polymer particles prepared by SPG emulsification and suspension polymerization

FT-IR spectra, vibrational assignments, and density functional calculations of imidazo[1,2-a]pyridine molecule and its Zn(II) halide complexes

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