Transmission of dipolar substituent effects:  ionization of a series 3-(7-substituted-1-naphthyl) propynoic acid (E)-3-(7-substituted-1-naphthyl) propenoic acids and their Esterification with Diazodiphenylmethane

Alkaline hydrolysis rates coefficients for the series of methyl 3-(7-substituted-1-naphthyl) propynoate was calculated in 70%v/v dimethylsulphoxide-water at various temperatures (25,30,40, and 50̊ C). The pKa values of 3-(7-substituted-1-naphthyl) propynoic acid and (E)- 3-(7-substituted-1-naphthyl) propenoic acid calculated in 80%w/w 2-methoxyethanol-water at room temperature (25.0̊ C). logk2 of esterification rate coefficients for 3-(7-substituted-1-naphthyl) propynioc acid and (E)-3(7-substituted-1-naphthyl) propenioc acid with DDM have been measured at 30.0̊ C. Reversed substituent dipolar effects were found in the ionization reaction. In the esterification reaction with DDM the result show similar but reduced substituted effects. Rate retardations was found in the alkaline hydrolysis. It could be result from steric effect or reversal of substituent dipolar effect with a combination of steric effect.

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The transmission of polar effects. Part X. The esterification with diazodiphenyl-methane and the ionization of 9-substituted 10-anthroic and 8-substituted 1-naphthoic acids

Canadian Journal of Chemistry ◽

10.1139/v69-025 ◽

1969 ◽

Vol 47 (2) ◽

pp. 185-190 ◽

Cited By ~ 11

Author(s):

Keith Bowden ◽

D. C. Parkin

Keyword(s):

Free Energy ◽

Ethyl Acetate ◽

Field Effect ◽

Isopropyl Alcohol ◽

Substituent Effects ◽

Butyl Alcohol ◽

Rate Coefficients ◽

Linear Free Energy ◽

Energy Relations ◽

Substituted 1

The rate coefficients for the reaction with diazodiphenylmethane in methanol, ethanol, isopropyl alcohol, t-butyl alcohol, 2-methoxyethanol, 2-n-butoxyethanol, and ethyl acetate at 30° and the pKa values in 80% 2-n-butoxyethanol–water of a series of 9-substituted 10-anthroic and 8-substituted 1-naphthoic acids have been determined. The effect of substitution has been analyzed by linear free energy relations. The variation in the susceptibilities of the systems to polar substituent effects with the medium are examined. The occurrence of reversed dipolar substituent effects in the reactions of the 1,8-naphthoic acids is detected. The implications of the results for the inductive and field effect models for the transmission of polar effects are discussed.

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The transmission of polar effects. Part V. The kinetics of esterification with diazodiphenylmethane and the ionization of substituted acetic and propionic acids in several solvents

Canadian Journal of Chemistry ◽

10.1139/v68-487 ◽

1968 ◽

Vol 46 (18) ◽

pp. 2929-2940 ◽

Cited By ~ 11

Author(s):

Keith Bowden ◽

M. Hardy ◽

D. C. Parkin

Keyword(s):

Isopropyl Alcohol ◽

Butyl Alcohol ◽

Rate Coefficients ◽

Esterification Reaction ◽

Linear Free Energy ◽

Ionization Reaction ◽

Reaction Constants ◽

Polar Substituents ◽

Energy Relations ◽

Kinetics Of

The rate coefficients for the reaction with diazodiphenylmethane in methanol, ethanol, isopropyl alcohol,t-butyl alcohol, 2-methoxyethanol, 2-n-butoxyethanol, dimethyl sulfoxide, ethyl acetate, and toluene at 30° and the pKa values in water, 50% ethanol–water, and 80% 2-methoxyethanol–water of 18 substituted acetic and propionic acids have been determined. A further 14 acids have been studied to a more limited extent. The effect of substitution has been estimated by linear free energy relations. The reaction constants for the ionization reaction are almost independent of the medium. This is interpreted as being due to the field effect of the proximate polar substituents passing through the molecular cavity almost alone. The occurrence of steric inhibition of solvation causing acid weakening for bulky multi-substitution is confirmed. The reaction constants for the esterification reaction are affected by the solvent. This is attributed to dependence on solvation of the transition state.

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Transmission of polar effects. Part XI. Polar and steric effects in the reactions of arylaliphatic carboxylic acids

Canadian Journal of Chemistry ◽

10.1139/v69-461 ◽

1969 ◽

Vol 47 (15) ◽

pp. 2775-2779 ◽

Cited By ~ 5

Author(s):

Keith Bowden ◽

R. C. Young

Keyword(s):

Carboxylic Acids ◽

Alkaline Hydrolysis ◽

Rate Coefficients ◽

Steric Effects ◽

Measured Rate ◽

Substituent Constants ◽

Esterification Rate ◽

Acid Catalyzed

The rate coefficients for the reaction with diazodiphenylmethane in ethanol at 30° and the acid-catalyzed esterification with methanol at 60° of a number of arylaliphatic carboxylic acids and their pKa values in 80% 2-methoxyethanol–water have been measured. Rate coefficients have also been measured for the alkaline hydrolysis in 70% dioxan–water of their 2-diethylaminoethyl esters at 45°. The pKa values and diazodiphenylmethane esterification rate coefficients were also measured for a series of 2-substituted fluorene-9-carboxylic acids. The latter results have been correlated by Hammett equations and the transmission of polar effects in fluorene is discussed. Polar and steric substituent constants are evaluated for the arylaliphatic systems. These values are used to successfully correlate the hydrolysis and ionization reactions using the Taft–Ingold equation.

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Kinetic study of hydrolysis of benzoates. part xxvii. ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous Bu4NBr

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc2008019 ◽

2009 ◽

Vol 74 (1) ◽

pp. 29-42 ◽

Cited By ~ 9

Author(s):

Vilve Nummert ◽

Mare Piirsalu ◽

Signe Vahur ◽

Oksana Travnikova ◽

Ilmar A. Koppel

Keyword(s):

Alkaline Hydrolysis ◽

Rate Constants ◽

Pure Water ◽

Substituent Effects ◽

Benzoic Acids ◽

Resonance Effects ◽

The Media ◽

Substituted Benzoic Acids ◽

Hydrolysis Of ◽

Ortho Substituent

The second-order rate constants k (in dm3 mol–1 s–1) for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, have been measured spectrophotometrically in aqueous 0.5 and 2.25 M Bu4NBr at 25 °C. The substituent effects for para and meta derivatives were described using the Hammett relationship. For the ortho derivatives the Charton equation was used. For ortho-substituted esters two steric scales were involved: the EsB and the Charton steric (υ) constants. When going from pure water to aqueous 0.5 and 2.25 M Bu4NBr, the meta and para polar effects, the ortho inductive and resonance effects in alkaline hydrolysis of phenyl esters of substituted benzoic acids, became stronger nearly to the same extent as found for alkaline hydrolysis of C6H5CO2C6H4-X. The steric term of ortho-substituted esters was almost independent of the media considered. The rate constants of alkaline hydrolysis of ortho-, meta- and para-substituted phenyl benzoates (X-C6H4CO2C6H5, C6H5CO2C6H4-X) and alkyl benzoates, C6H5CO2R, in water, 0.5 and 2.25 M Bu4NBr were correlated with the corresponding IR stretching frequencies of carbonyl group, (ΔνCO)X.

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Kinetic Study of Hydrolysis of Benzoates. Part XXVI. Variation of the Substituent Effect with Solvent in Alkaline Hydrolysis of Substituted Alkyl Benzoates

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20061557 ◽

2006 ◽

Vol 71 (11-12) ◽

pp. 1557-1570 ◽

Cited By ~ 10

Author(s):

Vilve Nummert ◽

Mare Piirsalu ◽

Ilmar A. Koppel

Keyword(s):

Kinetic Study ◽

Alkaline Hydrolysis ◽

Rate Constants ◽

Substituent Effect ◽

Substituent Effects ◽

Alkyl Substituent ◽

Solvent Parameters ◽

Substituent Constants ◽

Hydrolysis Of ◽

Main Factor

The second-order rate constants k2 (dm3 mol-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates C6H5CO2R have been measured spectrophotometrically in aqueous 0.5 M Bu4NBr at 50 and 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3, CH2CH3) and in aqueous 5.3 M NaClO4 at 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH). The dependence of the alkyl substituent effects on different solvent parameters was studied using the following equations: ∆ log k = c0 + c1σI + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆EσI + c7∆YσI + c8∆PσI ∆ log k = c0 + c1σ* + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆Eσ* + c7∆Yσ* + c8∆Pσ* . ∆ log k = log kR - log kCH3. σI and σ* are the Taft inductive and polar substituent constants. E, Y and P are the solvent electrophilicity, polarity and polarizability parameters, respectively. In the data treatment ∆E = ES - EH2O , ∆Y = YS - YH2O , ∆P = PS - PH2O were used. The solvent electrophilicity, E, was found to be the main factor responsible for changes in alkyl substituent effects with medium. When σI constants were used, variation of the polar term of alkyl substituents with the solvent electrophilicity E was found to be similar to that observed earlier for meta and para substituents, but twice less when σ* constants were used. The steric term for alkyl substituents was approximately independent of the solvent parameters.

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