scholarly journals Selective Bromocyclization of 5-Amino-4-Alkenyl-1,2,4-Triazole-3-Thione

2021 ◽  
Vol 12 (1) ◽  
pp. 498-507
Keyword(s):  
Acetic Acid ◽  
Dft Calculations ◽  
Nmr Spectra ◽  
Molecular Electrostatic Potential ◽  
Theoretical Calculations ◽  
Electron Localization ◽  
Spectra Analysis ◽  
Alternative Structures ◽  
Partial Charges ◽  
Electrophilic Agent

Here, we present a study on the regioselectivity cyclization of 5-amino-4-alkenyl-1,2,4-triazole-3-thiones. The presence of various nucleophilic centers causes the possibility of cyclization of an alkenyl fragment on different heteroatoms and the formation of a few alternative structures. Elemental bromine was utilized as an electrophilic agent, and two 6-(bromomethyl)-6-R-5,6-dihydro[1,3]thiazolo[2,3-c][1,2,4]triazol-3-amine hydrobromide salts were obtained as the only products when taking reaction in chloroform, acetic acid, or acetonitrile. The 1H and 13C APT NMR spectra analysis proved the formation of the 1,3-thiazolinium ring upon cyclization reaction. DFT calculations at the ωB97X-D3/6-311G(d,p) level of theory were utilized to analyze molecular electrostatic potential, electron localization function, and Hirshfeld atomic partial charges the intermediate bromonium cation. These theoretical calculations explain the experimentally observed regioselectivity.

scholarly journals High resolution-1Н NMR spectroscopy of oral liquid in young patients with wedge-shaped lesions

2021 ◽  
Vol 18 (4) ◽  
pp. 20-25
Author(s):  
A. V. Mitronin ◽  
E. A. Srebnaya ◽  
V. I. Privalov ◽  
A. A. Prokopov
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Nmr Spectra ◽  
Young Patients ◽  
Treatment Method ◽  
Spectra Analysis ◽  
Oral Rinse ◽  
Before And After ◽  
Oral Liquid

Aim. The comparison of saliva 1Н NMR spectra in patients with wedge-shaped lesions before and after treatment.Materials and methods. Saliva as a study material was taken from patients with wedge-shaped lesions before and after treatment. The treatment method was remineralizing therapy that included the use of the oral rinse containing zinchydroxyapatite. 1Н NMR spectroscopy was chosen as an investigation method.Results. In most cases it is noted that after treatment the content of propionic and butyric acids was on the rise in relation of acetic acid. Overall concentration of 1Н protons didn't change significantly.Conclusions. 1Н NMR spectra analysis shows organic acid distribution in oral liquid before and after treatment, which helps to evaluate its response.

Predicting13C NMR Spectra by DFT Calculations

2003 ◽  
Vol 107 (46) ◽  
pp. 9964-9973 ◽  
Author(s):  
Alessandro Bagno ◽  
Federico Rastrelli ◽  
Giacomo Saielli
Keyword(s):  
Dft Calculations ◽  
Nmr Spectra

Structural study and characterization of the dipeptide 2-[[5-amino-5-oxo-2-(phenylmethoxycarbonylamino) pentanoyl] amino] acetic acid by vibrational spectroscopy and DFT calculations

2013 ◽  
Vol 1031 ◽  
pp. 110-118 ◽  
Author(s):  
Patricio Leyton ◽  
Carolina Paipa ◽  
Andrés Berrios ◽  
Antonio Zárate ◽  
María Victoria Castillo ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Dft Calculations ◽  
Structural Study ◽  
Vibrational Spectroscopy

scholarly journals Combining solid-state NMR spectroscopy with first-principles calculations – a guide to NMR crystallography

2016 ◽  
Vol 52 (45) ◽  
pp. 7186-7204 ◽  
Author(s):  
Sharon E. Ashbrook ◽  
David McKay
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
First Principles ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
First Principles Calculations ◽  
Recent Developments ◽  
Future Potential ◽  
Nmr Crystallography

DFT calculations are an important tool in assigning and interpreting NMR spectra of solids: we discuss recent developments and their future potential in the context of NMR crystallography.

Orientationally Broadened NMR Spectra: Analysis by Special Processing Methods

ChemInform ◽  
2003 ◽  
Vol 34 (32) ◽  
Author(s):  
Frederick G. Vogt ◽  
Karl T. Mueller
Keyword(s):  
Nmr Spectra ◽  
Processing Methods ◽  
Spectra Analysis

Predicting the NMR spectra of nucleotides by DFT calculations: cyclic uridine monophosphate

2008 ◽  
Vol 46 (6) ◽  
pp. 518-524 ◽  
Author(s):  
Alessandro Bagno ◽  
Federico Rastrelli ◽  
Giacomo Saielli
Keyword(s):  
Dft Calculations ◽  
Nmr Spectra ◽  
Uridine Monophosphate

31P and 195Pt solid-state NMR and DFT studies on platinum(i) and platinum(ii) complexes

2018 ◽  
Vol 47 (27) ◽  
pp. 8884-8891 ◽  
Author(s):  
Stefano Todisco ◽  
Giacomo Saielli ◽  
Vito Gallo ◽  
Mario Latronico ◽  
Antonino Rizzuti ◽  
...  
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Pulse Sequence ◽  
Spin Orbit ◽  
Dft Studies ◽  
Relativistic Dft

31P and 195Pt solid state NMR spectra on anti-[(PHCy)ClPt(μ-PCy2)2Pt(PHCy)Cl] (3) and [(PHCy2)Pt(μ-PCy2)(κ2P,O-μ-POCy2)Pt(PHCy2)] (Pt–Pt) (4) were recorded under CP/MAS conditions (31P) or with the CP/CPMG pulse sequence (195Pt) and compared to data obtained by relativistic DFT calculations of 31P and 195Pt CS tensors and isotropic shielding at the ZORA Spin Orbit level.

scholarly journals Investigation of Some Antiviral N-Heterocycles as COVID 19 Drug: Molecular Docking and DFT Calculations

2020 ◽  
Vol 21 (11) ◽  
pp. 3922 ◽  
Author(s):  
Mohamed Hagar ◽  
Hoda A. Ahmed ◽  
Ghadah Aljohani ◽  
Omaima A. Alhaddad
Keyword(s):  
Dipole Moment ◽  
Molecular Docking ◽  
Dft Calculations ◽  
Binding Affinity ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Hydrophobic Interactions ◽  
Chemical Reactivity ◽  
Main Protease

The novel coronavirus, COVID-19, caused by SARS-CoV-2, is a global health pandemic that started in December 2019. The effective drug target among coronaviruses is the main protease Mpro, because of its essential role in processing the polyproteins that are translated from the viral RNA. In this study, the bioactivity of some selected heterocyclic drugs named Favipiravir (1), Amodiaquine (2), 2′-Fluoro-2′-deoxycytidine (3), and Ribavirin (4) was evaluated as inhibitors and nucleotide analogues for COVID-19 using computational modeling strategies. The density functional theory (DFT) calculations were performed to estimate the thermal parameters, dipole moment, polarizability, and molecular electrostatic potential of the present drugs; additionally, Mulliken atomic charges of the drugs as well as the chemical reactivity descriptors were investigated. The nominated drugs were docked on SARS-CoV-2 main protease (PDB: 6LU7) to evaluate the binding affinity of these drugs. Besides, the computations data of DFT the docking simulation studies was predicted that the Amodiaquine (2) has the least binding energy (−7.77 Kcal/mol) and might serve as a good inhibitor to SARS-CoV-2 comparable with the approved medicines, hydroxychloroquine, and remdesivir which have binding affinity −6.06 and −4.96 Kcal/mol, respectively. The high binding affinity of 2 was attributed to the presence of three hydrogen bonds along with different hydrophobic interactions between the drug and the critical amino acids residues of the receptor. Finally, the estimated molecular electrostatic potential results by DFT were used to illustrate the molecular docking findings. The DFT calculations showed that drug 2 has the highest of lying HOMO, electrophilicity index, basicity, and dipole moment. All these parameters could share with different extent to significantly affect the binding affinity of these drugs with the active protein sites.

Studies on Ylides: Reactions of N -Pyridinium Phenancylides with α,β-Unsaturated Ketones, I

1974 ◽  
Vol 29 (7-8) ◽  
pp. 552-555 ◽  
Author(s):  
Purshottam S. Kendurkar ◽  
Ram S. Tewari
Keyword(s):  
Acetic Acid ◽  
Nmr Spectra ◽  
Ammonium Acetate ◽  
Ir And Nmr Spectra ◽  
Unsaturated Ketones

Reactions of N-pyridinium phenancylides with different a, β-unsaturated ketones give 2,4,6-triarylsubstituted pyridines, 2,6-diphenyl-4-(2-pyridyl) pyridines, 2-benzylidene-4,6-diphenyl pyridines and 2,4,6-triphenyl-3-bromopyridine. Ammonium acetate in acetic acid was used as cyclization agent. The structure of the products are supported by IR and NMR spectra.

Hydrolysis of Zirconium Propoxide by an Esterification Reaction

1992 ◽  
Vol 271 ◽  
Author(s):  
I. Laaziz ◽  
A. Larbot ◽  
C. Guizard ◽  
A. Julbe ◽  
L. Cot
Keyword(s):  
Acetic Acid ◽  
Light Scattering ◽  
Crystalline Structure ◽  
Structure Determination ◽  
Nmr Spectra ◽  
Esterification Reaction ◽  
Zirconium Propoxide ◽  
Size Growth ◽  
Hydrolysis Of

ABSTRACTZirconium propoxide hydrolysis was performed with the help of an esterification reaction using acetic acid. Products, obtained according to the value of hydrolysis ratio, are successively crystals, sols and gels or precipitates. The similarity of FUR and NMR spectra for crystals and gels allows to think that the arrangements of ligands around the zirconium atoms are close. The crystalline structure determination permits to precise the environment : acetate groups are always bridging and propoxy groups can be bridging or terminal. Clusters containing 9 zirconium atoms, bridged by oxygen atoms, exist in the structure. The colloid size growth was performed by light scattering. A discussion of the role of acetic acid and the competition between the possible reactions is given.

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