Influence of medium on alkaline hydrolysis of succinic acid monomethyl and monopropyl esters

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.

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Kinetics of alkaline hydrolysis of mono- and dimethyl esters of 2,3- and 3,4-thiophenedicarboxylic acids, cyanothiophenecarboxylic acids and their dihydroanalogues

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19872005 ◽

1987 ◽

Vol 52 (8) ◽

pp. 2005-2018

Author(s):

Milan Struhárik ◽

Pavel Hrnčiar ◽

Dušan Loos

Keyword(s):

Kinetic Parameters ◽

Alkaline Hydrolysis ◽

Rate Constants ◽

Activation Parameters ◽

Hydrolysis Rate ◽

Electronic Effects ◽

Cyclic System ◽

Kinetics Of ◽

Hydrolysis Of ◽

Reactivity Order

Kinetics of alkaline hydrolysis of mono- and dimethyl esters of 2,3- and 3,4-thiophenedicarboxylic acids and their dihydroanalogues have been studied in 70% dioxane. The rate measurements have been carried out by the titrimetric method and the k1, k2 rate constants evaluated by the Frost-Schwemer method. The activation parameters of these reactions have been calculated. The results are compared with kinetic parameters of alkaline hydrolysis of methyl and dimethyl phthalates. The hydrolysis rate is significantly affected by the cyclic system to which the methoxycarbonyl groups are bound, the reactivity order being: Dihydrothiophene > thiophene > benzene. Also measured were the kinetics of alkaline hydrolyses of methyl 4-cyano-3-thiophenecarboxylate and 3-cyano-2-thiophenecarboxylate and of their dihydroanalogues. No meaningful preference of the hydrolysis of the group at the position 2 has been observed in case of 2,3-isomers. However, it has been confirmed that the hyper- and hypo-ortho transfer of electronic effects operates in the thiophene nucleus.

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Kinetics of alkaline hydrolysis of 3,4-thiophenedicarboxylic acid monomethyl ester in aqueous-nonaqueous media

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19881268 ◽

1988 ◽

Vol 53 (6) ◽

pp. 1268-1273

Author(s):

Ján Benko ◽

Oľga Vollárová

Keyword(s):

Methyl Alcohol ◽

Alkaline Hydrolysis ◽

Mixed Solvents ◽

Activation Parameters ◽

Butyl Alcohol ◽

Nonaqueous Media ◽

Alcohol Water ◽

Kinetics Of ◽

Hydrolysis Of ◽

Monomethyl Ester

The kinetics of alkaline hydrolysis of 3,4-thiophenedicarboxylic acid monomethyl ester has been studied in mixed solvents water-methyl alcohol, water-tert-butyl alcohol, and water-dioxane. The specific effects causing different courses of these dependences have been evaluated. The greatest changes in the thermodynamic activation parameters have been observed in the medium of water-methyl alcohol.

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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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The Kinetics of the Acidic and Alkaline Hydrolysis of Ethyl Thionbenzoate

The Journal of Organic Chemistry ◽

10.1021/jo01045a081 ◽

1963 ◽

Vol 28 (10) ◽

pp. 2825-2828 ◽

Cited By ~ 7

Author(s):

Stanley G. Smith ◽

Marion O'Leary

Keyword(s):

Alkaline Hydrolysis ◽

Kinetics Of ◽

Hydrolysis Of

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Isothermal and non-isothermal kinetics of hydrolysis of 1-[2-(2- pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]- perhydroazepinium chloride (BK 129)

Acta Facultatis Pharmaceuticae Universitatis Comenianae ◽

10.2478/afpuc-2013-0018 ◽

2013 ◽

Vol 60 (2) ◽

pp. 43-48

Author(s):

Stankovičová M. ◽

Bezáková Ž. ◽

Beňo P. ◽

Húšťavová P.

Keyword(s):

Biological Activity ◽

Alkaline Hydrolysis ◽

Functional Group ◽

Isothermal Kinetics ◽

Basic Part ◽

Buffer Solutions ◽

Kinetics Of Hydrolysis ◽

Short Time ◽

Kinetics Of ◽

Hydrolysis Of

Abstract The substance BK 129 - 1-[2-(2-pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]-perhydroazepinium chloride was prepared in terms of influence of the connecting chain between the carbamate functional group and the basic part of molecule on biological activity. Such a structural feature is important with regard to its stability. In this work we determined the rate constants of alkaline hydrolysis of this compound at increased temperature under isothermal and non-isothermal conditions. The hydrolysis was also performed in buffer solutions with the purpose of evaluating its stability. Non-isothermal tests of stability enable to reduce the number of analyses. The necessary data for stability of compound are in this way achieved in a short time.

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