Synthesis and Theoretical Calculations of 2-(p-Tolyl)-2,3-Dihydro-1H-Perimidine using Density Functional Theory (original) (raw)
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We report here the synthesis of phenyl(2-phenyl-2,3-dihydro-1H-perimidin-2-yl)methanone (2) by the condensation reaction between 1,8-diaminonaphthalene (1) and benzil in equimolar ratio at ambient temperature. Further reaction of compound 2 with one equivalent of sodium borohydride at 0 ºC resulted in quantitative conversion of ketone to corresponding alcohol, namely, phenyl(2-phenyl-2,3-dihydro-1H-perimidin-2-yl)methanol (3). The solid-state structures of both the compounds were established using single-crystal X-ray diffraction analysis. We probed, using quantum mechanics, the mechanism of formation of compound 2 through two of the most plausible routes and observed that it was more plausible that the first route, energy-wise, would result in product 2. We also calculated the stabilization energy of intermolecular hydrogen bonding, which leads to the formation of a dimer, which has already been observed in the solid-state structure of compound 3.
1. Introduction The chemistry of heterocyclic compounds is the most important in the discovery of new drugs. pyrimidine is one of the most important heterocycles with pharmacological activities because it is an essential constituent of all cells and thus of all living matter [i]. Hence, they have received the consideration of researchers due to its manifold implication viz, antibacterial, antifungal, anticancer, antitumor, antiallergic, analgesic, anti inflammatory, and antineuplastic [ii-iv]. Some pyrimidine derivatives are also reported as good corrosion inhibitors because of the presence of hetero atoms and delocalized π-electrons [v-vii].Generally, nitrogen containing heterocyclic compounds such as pyridine and pyrimidine derivatives favourable for NLO conditions due to the presence of lone pair electrons. Recently pyrimidine derivatives reported as a good non-linear material [viii-x]. In spite of the application of pyrimidine derivatives, a venture has been undertaken for the synthesis of 5-(3,5-difluoro-4-hydroxyphenyl)-5,6,7,8-tetrahydro-7-thioxopyrimido[4,5-d]-pyrimidine-2,4(1H,3H)-dione compound. The aim of present work is to study the structural activity of the DTTP molecule by using density functional theory. To best of our knowledge, there is no computational studies has been reported for the DTTP compound. Hence, the present investigation deals with using DFT method of calculations along with experimental measurements of FT-IR, FT-Raman spectra was undertaken to study the vibrational spectra of studied molecule completely and to identify the various normal modes with greater wave number accuracy. In this present study, optimized molecular structural parameters, HOMO-LUMO analysis and NLO property (first hyperpolarizability) are carried out to elucidate the information regarding energy gap and charge transfer within the molecule. In addition, molecular electrostatic potential (MEP), mulliken charge distribution and thermodynamic parameters of the DTTP compound are studied by using density functional theory.
Theoretical Study of the Chemical Reactivity of a Series of 2, 3-Dihydro-1H-Perimidine
International Research Journal of Pure and Applied Chemistry
This reactivity study was performed on seven molecules of a 2,3-dihydro-1H-perimidine series using density functional theory at the B3LYP / 6-311 G (d, p) level. Calculation of the dipole moment showed that compound 4 is more soluble in aqueous medium. The study of frontier molecular orbitals, in particular the energy gap (ΔE), electronegativity (c), chemical hardness (η) and the electrophilic index (ω) has provided a better overview molecular properties. Thus, the compound 5 with the highest energy gap between the boundary orbitals is the most stable and the least reactive. Analysis of local descriptors and the electrostatic potential map identified nitrogen atoms N26 and N28 as the preferred sites of electrophilic attack and the carbon atom C26 as the preferred site of nucleophilic attack.
Synthesis, characterization and biological activity of 2- Aryl -2, 3-dihydro-1H-perimidine
Research in Pharmaceutical Biotechnology, 2014
A series of new 2-Aryl-2,3-dihydro-1H-perimidine, derivatives (3a-j) were synthesized under reflux and at room temperature by condensation reaction of 1,8-diaminonaphthalene (2) with various substituted benzaldehyde using glacial acetic acid a catalyst. The synthesized compounds were characterized by spectroscopic methods, infrared (IR), proton nuclear magnetic resonance (1 H-NMR), carbon nuclear magnetic resonance (13 C-NMR) and carbon nuclear magnetic resonance-distortionless enhancement by polarization (13 C-NMR-DEPT). The synthesized compounds were screened for their biological activity against the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli. The results showed that 89% of the synthesized compounds were not active against S. aureus, while E. coli showed 100% sensitivity to the mentioned compound. These results illustrate the marked bactericidal effect of all the synthesized compounds.
Journal of Scientific Research, 2011
The structural and electronic properties of 3'(4-(5-oxo-5-piperidin1-1-yl)penta-1,3-dienyl)benzo[d][1,3]dioxol-2-yl]-thymidine molecule have been investigated theoretically by performing density functional theory (DFT/3-21G*, 6-31G* and 6-31G**). The geometry of the molecule is optimized, and the electronic properties and relative energies of the molecules have been calculated by density functional theory in the ground state. The resultant dipole moments of the studied molecule are about 5.5, 6.36 and 7.35 Debyes by three levels (3-21G*, 6-31G* and 6-31G**, respectively). This property makes it an active molecule with its environment that is this molecule may interacts with its environment strongly in solution.Keywords: 3'-Azido-3'-deoxythymidine (AZT); Piperine; Density functional theory (DFT); Thymidine.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i2.6364 J. Sci. Res. 3 (2), 339-345 (2011)
Materials Today: Proceedings, 2020
Electronic structure calculation explores the molecular structure and geometric conformations of the molecules from only the knowledge of its constituent atoms. In the present work, quantum mechanical calculations of a 3-phenyl-1-(methyl-sulfonyl)-1H-pyrazolo[3,4-d]pyrimidine-4-amine molecule have been performed by Density Functional Theory using the standard 6-31G** basis set with the GAUSSIAN09. The electronic structure, dipole moment, frontier orbitals energy, thermal parameters (entropy, enthalpy, internal energy, and Gibb's potential), Infrared (IR) spectral lines of the title molecule are elaborated. To study the chemical reactivity; molecular electrostatic potential (MEP) surface, HOMO-LUMO surface, and some other properties of the molecule were also investigated.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011
Quantum chemical calculations of energies, geometrical structural parameters, harmonic and anharmonic frequencies of 2,4-DCP and 4,6-DCP were carried out by HF and density functional theory methods with 6-311++G(d,p) as basis set. The assignment of each normal mode has been made using the observed and calculated frequencies, their IR and Raman intensities. A detailed interpretation of the FT-IR and FT-Raman spectra of 2,4-DCP and 4,6-DCP was reported on the basis of the calculated potential energy distribution (PED). A comparison of theoretically calculated vibrational frequencies at B3LYP/6-311++G(d,p) with FT-IR and FT-Raman experimental data shows good agreement between them. Natural atomic charges of 2,4-DCP and 4,6-DCP were calculated and compared with pyrimidine molecule.
Journal of Molecular Structure: …, 2001
The ground state molecular structure of different single-atom peri-bridged naphthalene compounds containing a fourmembered ring was studied by ab initio quantum chemistry and by density functional theory (DFT) using the Becke, Lee, Yang and Parr density functional method (B3LYP). Also, in some of these compounds, pyramidal atom inversion energy and its transition state structure along with the energetic stability of the favored intermediate in the electrophilic substitution, have been determined using these computational methods. q
Journal of Structural Chemistry, 2008
A systematic study was performed to examine the possibilities of the B3LYP DFT method in a dgdzvp fullelectron basis and of the method including a pseudopotential for iodine compounds. The full-electron basis generally gives better agreement for X-I bond lengths and reaction enthalpies of iodination of organic compounds and equally good agreement in calculations of the IR vibrations of the X-I bond length compared with the studies using the pseudopotential. The full-electron basis also allows adequate calculations of the quadrupole coupling constants of iodine atoms and is generally characterized by smaller computing times.
Journal of Molecular Structure, 2015
Quantum chemical calculations of energy, geometrical structure and vibrational wavenumbers of a potential chemotherapeutic agent namely, 5-propyl-6-(p-tolylsulfanyl)pyrimidine-2,4(1H,3H)-dione were carried out, using DFT method. Comprehensive interpretation of the experimental FT-IR and FT-Raman spectra of the compound under study is based on potential energy distribution. The difference between the observed and scaled wavenumbers of most of the normal modes is very small with B3LYP/6-311 þ þG(d,p) method. The UVeVis spectrum of the compound was recorded and the electronic properties, such as frontier orbitals and band gap energies were calculated by the TD-DFT approach. The values of the electric dipole moment, polarizability and first static hyperpolarizability of the title compound have also been investigated. NBO analysis has been performed to explain the charge transfer within the molecule along with the calculation of different thermo-dynamical properties.