Kinetics of the Esterification of Substituted Benzoic Acids

Hartman, R. J.; Gassmann, A. G.

doi:10.1021/ja01863a065

Cited by 11 publications

(5 citation statements)

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“…66. Radical decomposition of meta-and parasubstituted benzoyl peroxides in acetophenone. 67. Decomposition of phenylazotriphenylmethane in cyclohexane and a series of aromatic solvents.…”

Section: Solvent Changesmentioning

confidence: 99%

The Enthalpy-Entropy Relationship and Its Implications for Organic Chemistry

Leffler¹

1955

J. Org. Chem.

703

289

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When T = ß, AF* = AH0* and all the rate or equilibrium constants are the same within the precision of the relationship. Hence ß is called the isokinetic or isoequilibrium temperature and equation 4 the isokinetic relationship. Of course if ß is extremely far from the usual working temperature the relationship may be invalidated by changes in AH* with temperature. In that case ß is merely a slope and has no physical meaning. 1206

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“…66. Radical decomposition of meta-and parasubstituted benzoyl peroxides in acetophenone. 67. Decomposition of phenylazotriphenylmethane in cyclohexane and a series of aromatic solvents.…”

Section: Solvent Changesmentioning

confidence: 99%

The Enthalpy-Entropy Relationship and Its Implications for Organic Chemistry

Leffler¹

1955

J. Org. Chem.

703

289

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“…The synthesis of the new NAH compounds ( 3 – 5 ) was performed in three steps [ 4 ]. First, the esters ( 10a and 10b ) [ 26 , 27 ] were prepared by Yamada oxidation in methanol of the corresponding commercial aldehydes ( 9a and 9b ) [ 28 ], and then submitted to hydrazinolysis reaction in ethanol to produce the key hydrazide intermediates 11a and 11b ( Scheme 1 ) [ 29 , 30 ]. Finally, the desired NAH derivatives ( 3 – 5 ) were obtained in high overall yields by an acid-catalyzed condensation reaction with the corresponding aldehydes (2-formylthiophene or 2-formylselenophene, Scheme 1 ).…”

Section: Resultsmentioning

confidence: 99%

Effect of S–Se Bioisosteric Exchange on Affinity and Intrinsic Efficacy of Novel N-acylhydrazone Derivatives at the Adenosine A2A Receptor

et al. 2021

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In this work, we evaluated the conformational effect promoted by the isosteric exchange of sulfur by selenium in the heteroaromatic ring of new N-acylhydrazone (NAH) derivatives (3–8, 13, 14), analogues of the cardioactive compounds LASSBio-294 (1) and LASSBio-785 (2). NMR spectra analysis demonstrated a chemical shift variation of the iminic Csp2 of NAH S/Se-isosters, suggesting a stronger intramolecular chalcogen interaction for Se-derivatives. To investigate the pharmacological profile of these compounds at the adenosine A2A receptor (A2AR), we performed a previously validated functional binding assay. As expected for bioisosteres, the isosteric-S/Se replacement affected neither the affinity nor the intrinsic efficacy of our NAH derivatives (1–8). However, the N-methylated compounds (2, 6–8) presented a weak partial agonist profile at A2AR, contrary to the non-methylated counterparts (1, 3–5), which appeared as weak inverse agonists. Additionally, retroisosterism between aromatic rings of NAH on S/Se-isosters mimicked the effect of the N-methylation on intrinsic efficacy at A2AR, while meta-substitution in the phenyl ring of the acyl moiety did not. This study showed that the conformational effect of NAH-N-methylation and aromatic rings retroisosterism changed the intrinsic efficacy on A2AR, indicating the S/Se-chalcogen effect to drive the conformational behavior of this series of NAH.

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“…The mixture is then introduced into the tubular flow reactor. The final product can be collected and quenched at the tubing outlet and later analyzed by GC-MS or 1 H, 13 C NMR.…”

Section: Preliminary Batch 1 H Nmr Studiesmentioning

confidence: 99%

“…H NMR and13 C NMR experiments were performed with a Bruker (Wissembourg, France) Avance 300 Ultrashield spectrometer at room temperature in DMSO-d 6 and DMF-d 7 with calibration on the solvent peak. Chemical shifts are given in δ and coupling constants in Hz.Kinetics study under microflow -General procedureFor the study of reaction kinetics, every reagents benzoic acids, methyl iodide and TMGN were dissolved in DMF (16 ml, 0.02 mol.l -1 ) prior to use, flow rates (and residence time) were varied.…”

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confidence: 99%

Alkylation of carboxylic acids in a microfluidic device: kinetics parameters determination, Hammett reaction constant measurement and optimization of preparative experiment

Rolando

Penhoat

Gholamipour‐Shirazi

2009

Proceedings of the 13th International Electronic Conference on Synthetic Organic Chemistry

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A new proton sponge 1,8-bis(tetramethylguanidino)naphthalene (TMGN) was utilized for the alkylation of benzoic acid by iodomethane in a continuous flow microsystem. Using this set-up, kinetics of the reaction was determined in different mixing strategies and the Hammett reaction constant was measured.Good performance and efficiency of this procedure were confirmed through several preparative studies. Introduction:Chemical reactions are usually achieved by mixing of reagents or reagents/catalysts. 1 "Mixing" is a broad, generic term, which in a solution phase is defined as a phenomenon that creates homogeneity of all species in the solution. This is true if the mixing time is much shorter than the reaction time. In other words, if reaction is slower than mixing, the reaction proceeds in a homogeneous solution. 1 But there are some exceptions. Table 1 displays some mixing-sensitive reactions. Meanwhile, in general, decreasing the total mixing time to a level well below the time scale of the chemical reaction, is necessary to avoid the adverse effects of imperfect mixing on conversion and selectivity. 2 A facile technique for increasing the rate of mixing is to employ narrow, high aspect ratio reaction channels, hence increasing the interfacial surface area.During the current decade, the emergence and the development of microreactor technology offer to the synthetic chemists, innovative and alternative methods for mixing reagents with a better control on reactivity and selectivity. If extraordinary effects of such microreactor technology have been reported so far in synthetic chemistry, most of the fundamental physical and chemical phenomenons involved in such microdevices, responsible of such reactivity, have now to be quantified or/and elucidated.[a038]

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Kinetics of the Esterification of Substituted Benzoic Acids

Cited by 11 publications

References 0 publications

The Enthalpy-Entropy Relationship and Its Implications for Organic Chemistry

The Enthalpy-Entropy Relationship and Its Implications for Organic Chemistry

Effect of S–Se Bioisosteric Exchange on Affinity and Intrinsic Efficacy of Novel N-acylhydrazone Derivatives at the Adenosine A2A Receptor

Alkylation of carboxylic acids in a microfluidic device: kinetics parameters determination, Hammett reaction constant measurement and optimization of preparative experiment

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