2-Methyl-3-(3-methylisoxazol-5-yl)-4-oxo-4<i>H</i>-pyrido[1,2-<i>a</i>]pyrimidin-1-ium chloride

Lahmidi, Sanae; Ouasif, L. El; Jilalat, A.E.; Al-Garadi, Wedad; Essassi, El Mokhtar; Mague, Joel T.

doi:10.1107/s2414314616019787

Cited by 6 publications

(7 citation statements)

References 10 publications

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“…The thermodynamic activation parameters such as the activation apparent energy E a , the activation enthalpy ∆H* and the activation entropy ΔS* were calculated from the Arrhenius equation (4) and the transition state equation 5 The energies of the activations of the three compounds are superior to those of the acid medium. This result confirms that our molecules are adsorbed into the surface of the metal by forming physical bonds (physisorption) [46]. Furthermore, positive signs of activation enthalpies revels the endothermic nature of the process of dissolving steel.…”

Section: Thermodynamic Parameters Of the Activation Corrosionsupporting

confidence: 81%

Experimental, quantum chemical studies of oxazole derivatives as corrosion inhibitors on mild steel in molar hydrochloric acid medium

2018

Int. J. Corros. Scale Inhib.

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The corrosion inhibition performances of (4-ethyl-2-phenyl-4,5-dihydro-1,3-oxazol-4-yl)methanol (C1); 4-{[(4-ethyl-2-phenyl-4,5-dihydro-1,3-oxazol-4-yl)methoxy]methyl}benzene-1-sulfonate (C2) and 4-[(azidoxy)methyl]-4-ethyl-2-phenyl-4,5-dihydro-1,3oxazole (C3) mild steel in molar hydrochloric solution have been evaluated by using gravimetric, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques as well as quantum chemical calculations. Results obtained reveal that these compounds reduce significantly the corrosion rate of mild steel, their inhibition efficiencies increased with inhibitor concentration. This behavior means that the inhibitive effect of the studied oxazole derivatives occur through the adsorption of inhibitor molecules on the metal surface. Polarization curves reveal that both compounds C1 and C3 act essentially as mixed type inhibitors with cathodic predominance effect, while the compound C2 can be classified as cathodic type inhibitor. EIS spectra obtained show a typical Nyquist plot with single semicircles shifted along the real impedance of x-axis. Impedance data are analyzed in term of the simple modified Randles equivalent circuit with one relaxation time constant. Indeed, a Constant phase element, CPE, is introduced in the circuit instead of a pure double layer capacitor in order to take into account the electrode surface heterogeneity. Adsorption of these inhibitors on the mild steel surface was found to obey the Langmuir adsorption isotherm. Some thermodynamic parameters were calculated and discussed. The correlation between inhibition efficiency and molecular structure of oxazole derivatives was theoretically studied via quantum chemical calculations using density functional theory (DFT) at B3LYP/6-31G (d,p). Results showed a general correlation between the computed descriptors and the experimental data.

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Section: Thermodynamic Parameters Of the Activation Corrosionsupporting

confidence: 81%

Experimental, quantum chemical studies of oxazole derivatives as corrosion inhibitors on mild steel in molar hydrochloric acid medium

2018

Int. J. Corros. Scale Inhib.

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“…[20] We have also showed that the heterocyclic β-diketone 4 has been condensed with a variety of nucleophilic reagents to give new heterocyclic systems containing pyridopyridine, pyrazole, isoxazole, hydroxyl-quinazoline moieties. [21][22][23][24] In continuation of our research work in this area, we studied the condensation of compound 4 with 5-amino-3-cyano-4-methyl-pyrazole 1 in refluxing ethanol for 24 hr. The reaction leads to the formation of the unexpected bipyrazolopyrimidine 3 next to pyridopyrimidinone 6 which were separated by silica gel column chromatography to afford 45% of compound 3 and 8% of 6 (Scheme 2).…”

Section: Plausible Mechanism Of the Synthesis Ofmentioning

confidence: 99%

A new synthetic route for the preparation of 2,2′,5′‐trimethyl‐7‐oxo‐4,7‐dihydro‐[6,7′‐bipyrazolo[1,5‐a]pyrimidine]‐3,3′‐dicarbonitrile, structural elucidation, Hirshfeld surface analysis, energy framework, density functional theory and molecular docking investigations

Hafi

Lahmidi

Boulhaoua

et al. 2022

J Chinese Chemical Soc

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A new bipyrazolo [1,5‐a]pyrimidine derivative, 2,2′,5′‐trimethyl‐7‐oxo‐4,7‐dihydro‐[6,7′‐bipyrazolo[1,5‐a]pyrimidine]‐3,3′‐dicarbonitrile dihydrate acetic acid solvate (3) has been synthesized via two different methods and characterized by single‐crystal X‐ray diffraction (XRD) and spectroscopic techniques. A plausible reaction mechanism in the synthesis of 3 through the two synthetic routes used has been proposed. The XRD analysis reveals that the two bicyclic moieties in 3 are close to perpendicular to one another. Some formal double bonds appear localized while others appear to involve some delocalization. In the crystal structure, a layer structure is formed by OH⋯O, OH⋯N and NH⋯O hydrogen bonds, along with weak CH⋯O and π‐stacking interactions. The energy framework indicates that the packing of 3 is mainly determined by dispersion interactions between molecules. The frontier molecular orbital analysis shows that 3 may act more as a nucleophile than an electrophile. The analysis of the Hirshfeld surface maps and 2D fingerprint plots of 3 reveal that intermolecular hydrogen bonding and H⋯H, N⋯H and O⋯H contacts are the major ones between the units of 3. The antibacterial activity of 3 is explored by its molecular docking into the binding site of tyrosyl‐tRNA synthetase, where it formed a stable complex with the amino acids of tyrosyl‐tRNA synthetase mainly through hydrogen bonding.

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“…The adsorption isotherm describes the type of interaction between the molecules of the inhibitors (FM1, FM2 and FM3) and the MS surface. The FMs molecules adsorb on MS/solution interface by the dislocation of water molecules as shown [10]:…”

Section: Adsorption Isothermmentioning

confidence: 99%

3,6-Di(pyridin-2-yl) pyridazine derivatives as original and new corrosion inhibitors in support of mild steel: Experimental studies and DFT investigational

2019

Int. J. Corros. Scale Inhib.

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Corrosion inhibition performance of three new synthesized novel compounds namely, 1-((3,6di(pyridin-2-yl)pyrdazin-4-yl)methyl)-indoline-2,3-dione (FM1), 4-(morpholinomethyl)-3,6di(pyridin-2-yl)pyridazine (FM2) and 3,6-di(pyridin-2-yl)-4-(p-tolyl)-pyridazine (FM3) on mild steel (MS) was investigated by HCl with 1 M concentration. The corrosion inhibition performance of the synthesized compounds was studied by weight lοss, impedance spectroscopy(EIS) and potentiodynamic polarization (PDP) methods. The results showed that tһe corrosion inhibition efficiency increases with the increase in the concentration of the compounds (FMs). The PDP measurements reveal that the type of these compounds is a mixed-type behavior. The results of impedance studies (EIS) showed that in the presence of FMs, the R ct values increase while the C dl values decrease due to the adsorption of inhibitors (FMs) on the mild steel surface. EIS study showed that there is one capacitance loop related to charge transfer mechanism. The adsorption of (FMs) on the mild steel surface obeys the Langmuir-adsorption isοtherm. The 1-((3,6-di(pyridin-2-yl)pyrdazin-4-yl)methyl)-indoline-2,3-dione (FM1) showed a better inhibition performance in comparison with the FM2 and FM3. The theoretical results which shows also a good correlation with the electrochemical experiments and weight loss measurements.

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2-Methyl-3-(3-methylisoxazol-5-yl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-1-ium chloride

Cited by 6 publications

References 10 publications

Experimental, quantum chemical studies of oxazole derivatives as corrosion inhibitors on mild steel in molar hydrochloric acid medium

Experimental, quantum chemical studies of oxazole derivatives as corrosion inhibitors on mild steel in molar hydrochloric acid medium

A new synthetic route for the preparation of 2,2′,5′‐trimethyl‐7‐oxo‐4,7‐dihydro‐[6,7′‐bipyrazolo[1,5‐a]pyrimidine]‐3,3′‐dicarbonitrile, structural elucidation, Hirshfeld surface analysis, energy framework, density functional theory and molecular docking investigations

3,6-Di(pyridin-2-yl) pyridazine derivatives as original and new corrosion inhibitors in support of mild steel: Experimental studies and DFT investigational

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