29368-59-0

Upstream product

• 69-93-2 uric Acid 
• 6119-32-0 4-methoxyphenoxyl 
• 1200-06-2 4-methoxyphenyl acetate 
• 75761-89-6 4-methoxyphenyl fluorene-9-carboxylate 
• 30924-74-4 thiobenzoic acid O-(4-methoxyphenyl) ester 
• 1523-19-9 4-methoxyphenyl benzoate 
• 18959-03-0 3,5-dinitro-benzoic acid-(4-methoxy-phenyl ester) 
• 26971-83-5 4-methoxybenzenethiolate 
• 74378-76-0 2-p-methoxyphenoxy-2-oxo-trans-5,6-tetramethylene-1,3,2-dioxaphosphorinane 
• 74378-76-0 2-p-methoxyphenoxy-2-oxo-trans-5,6-tetramethylene-1,3,2-dioxaphosphorinane 
• 114444-46-1 C₁₄H₁₃NO 
• 150-76-5 4-methoxy-phenol 
• 22113-51-5 p-cresolate 

Downstream Products

• 1200-06-2 4-methoxyphenyl acetate 
• 18938-17-5 4-formylphenoxide ion 
• 126083-72-5 C₁₃H₆N₅O₁₀^(1-) 
• 100-02-7 4-nitro-phenol 
• 146744-28-7 trans-2-(4-methoxyphenoxy)cyclohexanol 
• 132177-66-3 3,5-Dinitro-benzoic acid (3aR,5R,6R,7aR)-6-(4-methoxy-phenoxy)-2,2-dimethyl-hexahydro-benzo[1,3]dioxol-5-yl ester 
• 903-96-8 4-Methoxy-phenol-pikrylaether 
• 14609-74-6 p-nitrophenolate 
• 60154-37-2 3,4-dinitrophenoxide ion 
• 16554-54-4 3-nitrophenolate anion 
• 116883-43-3 O,O′-bis(4-methoxyphenyl) thiocarbonate 
• 14609-76-8 4-cyanophenolate 

Relevant academic research and scientific papers

Reinterpretation of curved hammett plots in reaction of nucleophiles with aryl benzoates: Change in rate-determining step or mechanism versus ground-state stabilization

A kinetic study is reported for the reaction of the anionic nucleophiles OH-, CN-, and N3- with aryl benzoates containing substituents on the benzoyl as well as the aryloxy moiety, in 80 mol % H2O-20 mol % dimethyl sulfoxide at 25.0 °C. Hammett log k vs σ plots for these systems are consistently nonlinear. However, a possible traditional explanation in terms of a mechanism involving a tetrahedral intermediate with curvature resulting from a change in rate-determining step is considered but rejected. The proposed explanation involves ground-state stabilization through resonance interaction between the benzoyl substituent and the electrophilic carbonyl center in the two-stage mechanism. Accordingly, the data are nicely accommodated on the basis of the Yukawa-Tsuno equation, which gives linear plots for all three nuceophiles. Literature reports of the mechanism of acyl transfer processes are reconsidered in this light.

Curved Hammett Plot in Alkaline Hydrolysis of O-Aryl Thionobenzoates: Change in Rate-Determining Step versus Ground-State Stabilization

Second-order rate constants have been measured for alkaline hydrolysis of O-aryl thionobenzoates (X-C6H4-CS-OC6H 4-Y) in 80 mol % H2O-20 mol % DMSO at 25.0 ± 0.1 °C. The Hammett plot for the reaction of O-4-nitrophenyl X-substituted thionobenzoates (X-C6H4-CS-OC6H 4-NO2, 1a-e) exhibits a downward curvature. However, a possible traditional explanation in terms of a change in the rate-determining step (RDS) has been considered but rejected. The proposed explanation involves stabilization of the ground-state (GS) through-resonance interaction between the electron-donating substituent X and the thionocarbonyl functionality on the basis of the linear Yukawa-Tsuno plot obtained for the same reaction. The Bronsted-type plot for the reaction of O-aryl thionobenzoates (C 6H5-CS-OC6H4-Y, 2a-i) is linear but exhibits many scattered points with a small βlg, (-0.35). The Hammett plot for the same reaction shows rather poor correlation with σ- constants but much better correlation with σ° constants. The alkaline hydrolysis of O-aryl thionobenzoates (1a-e and 2a-i) has been proposed to proceed through an addition intermediate in which bond formation is the RDS.

Electrochemistry of electron transfer probes. α-aryloxyacetoveratrones and implications for the mechanism of photo-yellowing of pulp1

Standard potentials (Eo) of a series of substituted α-aryloxyacetoveratrone derivatives have been determined from a correlation of the 13C NMR chemical shifts of the carbonyl group and a similar correlation (Eo vs. 13C NMR shifts) within a series of α-anilinoacetoveratrones. Using these potentials the rate constants for fragmentation of the radical anions were determined by digital simulation of the voltammetric waves. The rate contants for C O cleavage in the radical anions correlate with the pKa of the corresponding phenols. The fragmentations are all in the activated region of a general free energy relationship for this class of compound (α = 0.5). The standard potential and rate constant for fragmention of the α-guaiacoxyacetoveratrone radical anion also were determined. This species is a model compound for one of the lignin substructures. The implication of these results on the currently accepted mechanism for photo-yellowing of lignin rich paper is discussed.

Electrochemistry of electron-transfer probes. The role of the leaving group in the cleavage of radical anions of α-aryloxyacetophenones

The formal reduction potential (E°) of α-phenoxyacetophenone has been determined from the voltammetric peak potential obtained by linear sweep voltammetry in combination with the rate constant for fragmentation of the radical anion which had been determin

Reduction potentials and kinetics of electron transfer reactions of phenylthiyl radicals: Comparisons with phenoxyl radicals

The reduction potentials relative to the standard hydrogen electrode (SHE) for a number of para-substituted phenylthiyl radicals (Eo(p-XC6H4S./p-XC6H 4S-)) have been derived from pulse radiolytic studies of electron transfer equilibria which compare their values to those of radicals of known reduction potentials. A ladder combining the reduction potentials for both phenylthiyl and phenoxyl radicals has been established. These reduction potentials have been shown to be self-consistent and are intermediate between those of p-benzosemiquinone radical anion at 0.02 V and phenoxyl radical at 0.79 V. The reduction potential decreases as the electron donating power of the para substituent rises. The substituent effect is, however, much weaker for the phenylthiyl radicals than for their oxygen analogs. These observations demonstrate that the electronic interaction between the sulfur atoms and the aromatic ring system is much less than that which occurs with oxygen atoms. Examination of the rates of electron transfer in terms of the Marcus theory indicates that the reorganization energies of both p-XC6H4O. and p-XC6H4S. radicals are similarly affected by H, CH3, and CH3O substitution. However, the reorganization energies increase substantially for H2N and O- para substituents with the effect being much less for the p-XC6H4S. radicals than for the p-XC6H4O. radicals. These observations are in accord with structural information from spectroscopic and theoretical studies of the radicals which show that in the latter system the substituent groups interact strongly with the aromatic π system.

ALKALINE HYDROLYSIS OF SUBSTITUTED PHENYL ACETATES CATALYZED BY QUATERNARY AMMONIUM SALTS

Alkaline hydrolysis of the phenyl acetates CH3COOC6H4X (X = 4-NO2, 3-NO2, 3-Cl, H, 4-CH3, 3-CH3, and 4-OCH3) in the presence of hexadecyltris(2-hydroxyethyl)ammonium chloride, bis(2-hydroxyethyl)hexadecyl(methyl)ammonium bromide, and hexadecyltrimethylamm

A systematic entropy relationship for the general-base catalysis of the deprotonation of a carbon acid. A quantitative probe of transition-state solvation

The general-base-catalyzed deprotonation of a carbon acid, the l-methyl-4-(phenylacetyl)pyridinium cation (pKa = 9.02 at 25 °C), has been investigated for 32 general-base catalysts (25 amines and seven phenoxide ions) in aqueous solution. Amines give a generally scattered Bronsted plot; ring-substituted benzylamines have ?= 0.52, and ring-substituted phenoxides have ?= 0.60, with the phenoxides being more reactive than amines of similar basicity. The temperature dependences of the general-base-catalyzed deprotonation of this carbon acid have been measured over the range 15-45 °C for 12 base catalysts (eight primary, secondary, and tertiary amines; 4-(dimethylamino)pyridine; two phenoxide ions; hydroxide ion). The entropies of activation for these deprotonations show a clean curvilinear dependence upon the entropies of protonation of these base species, with the hydroxide ion being the only significant deviant from this relationship. This observation quantitatively establishes the importance of solvation effects as the major source of deviations that are commonly observed in Bronsted relationships for general-base-catalyzed processes.

The one-electron reduction potential of 4-substituted phenoxyl radicals in water

By means of pulse radiolysis the one-electron reduction potentials of twelve 4-substituted phenoxy radicals have been determined. The main reference used was the ClO2./ClO2- couple. By combining the redox potentials of phenoxyl radicals with the aqueous acidities of phenols the bond strength of the phenolic O-H bond was calculated. These values were found to be in good agreement with O-H bond dissociation enthalpies measured in the gas phase.

Antioxidation Mechanisms of Uric Acid

One-electron oxidation of uric acid generates the urate radical, which was studied in aqueous solution by pulse radiolysis and oxygen-uptake measurements.Acid-base properties of the uric acid radical were determined, i.e., pKa1 = 3.1 +/- 0.1 and pKa2 = 9.5 +/- 0.1.The reaction of the radical with oxygen was too slow to be measured, k 3 mol-1 s-1.The one-electron-redox potential vs NHE, E7 = 0.59 V, was derived from the pH dependence of the redox potential, which was fitted trough the values measured at pH 7 and 8.9 and those previously at pH 13.Rapid reactions of uric acid with oxidizing species and peroxy radicals were indicative of uric acid as a possible water-soluble physiological antioxidant.Rapid reaction of uric acid with the guanyl radical indicates that uric acid may also act as a repair agent of oxidative damage to DNA bases.