- Theoretical investigations on the HOMO–LUMO gap and global reactivity descriptor studies, natural bond orbital, and nucleus-independent chemical shifts analyses of 3-phenylbenzo[d]thiazole-2(3H)-imine and its para-substituted derivatives: Solvent and subs
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Natural bond orbital analysis, salvation, and substituent effects of electron-releasing (–CH3, –OH) and electron-withdrawing (–Cl, –NO2, –CF3) groups at para positions on the molecular structure of synthesized 3-phenylbenz
- Miar, Marzieh,Shiroudi, Abolfazl,Pourshamsian, Khalil,Oliaey, Ahmad Reza,Hatamjafari, Farhad
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- NEW ROUTE for the SYNTHESES of SOME NOVEL DERIVATIVES of 3-ARYL BENZO[d] THIAZOLE-2(3H)-IMINE from HIGH SUBSTITUTED THIOUREAS
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We have developed herein a new approach to the diverse synthesis of novel derivatives of 3-aryl benzo[d]thiazole-2(3H)-imines (3a?g), by a two-component reaction between diazonium salt (2) and various synthesized N-acyl-N'-aryl thioureas (1a?g), in the presence of sodium tert-butoxide as strong base. Finally, it resulted in the production of the desired products with a moderate yield. The chemical structures of these synthesized compounds were confirmed by various physico-chemical methods viz. FT-IR, 1H-NMR, 13C-NMR, and elemental analysis.
- Miar, Marzieh,Pourshamsian, Khalil,Shiroudi, Abolfazl,Hatamjafari, Farhad,Reza Oliaey, Ahmad
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p. 4853 - 4856
(2020/11/16)
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- Experimental and theoretical studies on the thermal decomposition of heterocyclic nitrosimines
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A series of substituted 2-nitrosiminobenzothiazolines (2) were synthesized by the nitrosation of the corresponding 2-iminobenzothiazolines (6). Thermal decomposition of 2a-f and of the seleno analogue 7 in methanol and of 3-methyl-2-nitrosobenzothiazoline (2a) in acetonitrile, 1,4-dioxane, and cyclohexane followed first-order kinetics. The activation parameters for thermal deazetization of 2a were measured in cyclohexane (ΔH? = 25.3 ± 0.5 kcal/mol, ΔS? = 1.3 ± 1.5 eu) and in methanol (ΔH? = 22.5 ± 0.7 kcal/mol, ΔS? = -12.9 ± 2.1 eu). These results indicate a unimolecular decomposition and are consistent with a proposed stepwise mechanism involving cyclization of the nitrosimine followed by loss of N2. The ground-state conformations of the parent nitrosiminothiazoline (9a) and transition states for rotation around the exocyclic C=N bond, electrocyclic ring closure, and loss of N2 were calculated using ab initio molecular orbital theory at the MP2/6-31G* level. The calculated gas-phase barrier height for the loss of N2 from 9a (25.2 kcal/mol, MP4(SDQ, FC)/6-31G*//MP2/6-31G* + ZPE) compares favorably with the experimental barrier for 2a of 25.3 kcal/mol in cyclohexane. The potential energy surface is unusual; the rotational transition state 9a-rot-ts connects directly to the orthogonal transition state for ring-closure 9aTS. The decoupling of rotational and pseudopericyclic bond-forming transition states is contrasted with the single pericyclic transition state (15TS) for the electrocyclic ring-opening of oxetene (15) to acrolein (16). For comparison, the calculated homolytic strength of the N-NO bond is 40.0 kcal/mol (MP4(SDQ, FC)/6-31G* + ZPE).
- Bartsch,Yeh Moon Chae,Ham,Birney
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p. 7479 - 7486
(2007/10/03)
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