Spectroscopic Studies of Some Imidazo[1,2-a]pyridine and Imidazo[1,2-a]pyrimidine Derivatives

Rackham, David M.

doi:10.1366/0003702794925129

Cited by 10 publications

(6 citation statements)

References 5 publications

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“…Fischer and Naaman [11] measured the infrared spectrum of imidazo [1,2-a]pyridine in the vapour phase and analysed the electronic absorption spectrum of the S 1 -S 0 transition. Rackham [12] recorded the fluorescence, UV, and infrared spectra of imidazo [1,2-a]pyridine, and of some of its derivatives.…”

Section: Introductionmentioning

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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Section: Introductionmentioning

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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“…A solution of 4.8 g (0.05 mole) of 2-aminopyrazine and 9.5 g (0.05 mole) of 6 in 80 ml of anhydrous ethanol was refluxed for 5 hours and then worked up in a manner identical to that described for 7e to afford the required compound in form of colorless crystals (0.8 g, 8 Anal. Calcd.…”

Section: -Trifluoromethylimidazo[l2-a]pyrazine (7f)mentioning

confidence: 99%

“…Found: C, 51.3; H, 2.8; F, 30.2; N, 15.2. 2-Hydroxy-2-trifluoromethyl-2,3-dihydro-l~~imidazo[ l,Z-a]pyridin-4-ium Bromide(8).The precipitate obtained as described in the above procedure was crystallized from ethanol to obtain 17 g (60%) of colorless crystals, mp >270° dec; nmr (hexadeuterodimethyl sulfoxide): 6 4.86 and 5.14 (2 doublets, 2H in position 3, J = 16 Hz), 7.22 (m, H-6 and H-8, ZH),8.17 (split t, H-7, lH),8.39 (split d, H-5, lH), 8.72 and 9.58 (2 broad singlets, 2-OH and 1-NH, 1H each).Anal. Calcd.…”

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confidence: 99%

Research on heterocyclic compounds. XX. Synthesis of trifluoromethyl derivatives of fused imidazole systems

Abignente

Caprariis

Patscot

et al. 1986

Journal of Heterocyclic Chem

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A series of heterocyclic compounds having an imidazole ring fused with another ring with a bridgehead nitrogen atom and bearing a trifluoromethyl moiety was synthesized by reaction of 3‐bromo‐1,1,1‐trifluoroacetone with various heteroarylamines. In some cases, an intermediate compound obtained together with the required product was isolated and its structure was elucidated: e.g., starting from 2‐aminopyridine we have obtained 2‐trifluoromethylimidazo[1,2‐a]pyridine and 2‐hydroxy‐2‐trifluoromethyl‐2,3‐dihydro‐1H‐imidazo [1,2‐a]pyridinium bromide. Such results confirmed the mechanism previously proposed for this reaction.

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“…While the amino or dimethylamine substitution at the 4′‐position cause a red shift of the fluorescence in polar solvents . The replacement of methyl by trifluoromethyl triggers a blue shift . Despite these observations, the development of more efficient fluorophores and bioactive compounds is a field of growing interest, making necessary the evaluation of new methodologies for the synthesis of imidazo[1,2‐ a ]pyridine derivatives with varied substituents allowing the modulation of the physicochemical properties and therefore, their activity and applications.…”

Section: Introductionmentioning

confidence: 99%

Microwave‐assisted synthesis and luminescent activity of imidazo[1,2‐a]pyridine derivatives

Rodríguez

Maldonado

Ramírez‐García

et al. 2020

Journal of Heterocyclic Chem

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In this work, a series of phenacyl bromide derivatives was synthesized and employed as key intermediate for the synthesis of substituted imidazo [1,2-a]pyridines. First, phenacyl bromide molecules were obtained from the bromination reaction of acetophenones assisted by microwave irradiation, obtaining the products 4a-v in a 15 minutes reaction with yields in the range of 50% to 99%. Subsequently, the conjugation of these molecules with 2-aminopyridine conduced to the production of imidazo[1,2-a]pyridine derivatives (7a-v) in a 60-second reaction with yields of 24% to 99%. Improved yields were determined with respect to those obtained with more tedious methodologies like thermally and mechanically assisted routes. Intense luminescence emissions in the purple and blue regions of the electromagnetic spectra were observed under UV excitation according to the nature of the substituents. This environmentally friendly methodology is expected to constitute an important class of organic compounds for the development of biomarkers, photochemical sensors, and medicinal applications.

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Spectroscopic Studies of Some Imidazo[1,2-a]pyridine and Imidazo[1,2-a]pyrimidine Derivatives

Cited by 10 publications

References 5 publications

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

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

Research on heterocyclic compounds. XX. Synthesis of trifluoromethyl derivatives of fused imidazole systems

Microwave‐assisted synthesis and luminescent activity of imidazo[1,2‐a]pyridine derivatives

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