- Two pathways of arenesulfonyl chlorides hydrolysis. Anionic intermediates in SAN-hydrolysis of 4-nitrobenzenesulfonyl chloride
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Arenesulfonyl chlorides undergo the hydrolysis in water and binary aqueous solvents along two pathways of SAN mechanism involving cyclic intermediate with pentacoordinate sulfur atom (H2O) nSO2(Cl)Ar and through anionic intermediate HO -SO2(Cl)Ar(H2 O)n. The contribution of the process involving anionic intermediates grows with increasing σp constant and attained maximum value for 4- nitrobenzenesulfonyl chloride. In water and 17 water-dioxane mixtures the relation of apparent first-order rate constants and activation parameters to the molar fraction of dioxane in the mixture (0-0.25) are not monotonic, and the hydrolysis process is catalyzed by dioxane.
- Ivanov,Gnedin,Kislov
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- Solvolysis of Allyl Arenesulfonates. Cautionary Comments concerning the NOTs Scale of Solvent Nucleophilicities
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The rates of solvolysis of five allyl arenesulfonates are analysed in terms of the extended Grunwald-Winstein equation.The l values are constant but the m values decrease slightly as the nucleofugality of the leaving group increases.The solvent nucleophilicity (NOTs) values presently available in the literature are based upon a m value for methyl p-toluenesulfonate (tosylate) solvolysis of 0.3; it is demonstrated that a value of 0.55 is more appropriate.The previously reported l values and correlation coefficients for tosylate ester solvolyses are accurate and the "ap parent" sensitivities to solvent ionizing power (m values) are easily corrected.However, for use in conjunction with solvent ionizing power scales for other leaving groups, NTs values based on the appropriate m value or, alternatively, NEt3O+%& values (based on triethyloxonium ion solvolysis) are required.
- Kevill, Dennis N.,Rissmann, Thomas J.
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- Solvolysis of 2-Propyl 4-Nitrobenzenesulfonate in 1,1,1,3,3,3-Hexafluoro-2-propanol
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The reaction of the halide nucleophiles and of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) with methyl 4-nitrobenzenesulfonate (methyl nosylate) and 2-propyl nosylate was examined in the solvent 1,1,1,3,3,3-hexafluoro-2-propanol.A plot of the logarithm of the second-order rate constant, k(nuc), for reaction of the halides and solvent with 2-propyl nosylate against log k(nuc) for reaction with methyl nosylate is linear and has a slope of 0.34.The point corresponding to the reaction with HFIP falls on the same line as the halide nucleophiles.On the basis of these results, it is suggested that the solvolysis in HFIP of the simple secondary compound 2-propyl nosylate may be occuring by a concerted S(N)2 mechanism and may not involve an ion-pair intermediate
- Dietze, Paul E.,Hariri, Rahim,Khattak, Jamila
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- Evaluation of O-alkyl and aryl sulfonyl aromatic and heteroaromatic amidoximes as novel potent DNA photo-cleavers
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Several stable O-alkyl and aryl sulfonyl conjugated p-nitro-Ph and o-, m-, p-pyridine N′-hydroxy imidamides, were subjected to UV irradiation at 312 nm with supercoiled circular plasmid DNA pBluescript KS II. The generated amidinyl and sulfonyloxyl radicals led to effective DNA photo-cleavage. Both alkyl and aryl sulfonyl derivatives were active and the order p-pyridine > p-nitro-Ph > o-pyridine > m-pyridine was schematized for the N′-hydroxy imidamides moiety. Calf thymus-DNA affinity studies which comprised UV interactions, viscosity experiments and competitive studies with ethidium bromide showed good to excellent affinity of the compounds. These properties revealed sulfonyl amidoximes as novel effective DNA-photo-cleavers and may serve in the discovery of new leads for "on demand" biotechnological and medical applications.
- Papastergiou,Perontsis,Gritzapis,Koumbis,Koffa,Psomas,Fylaktakidou
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- Kinetics of arylsulfonation of aminobenzoic acids with m-and p-nitrobenzenesulfonyl chlorides in the system water-2-propanol
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The concentrations of the uncharged and anionic forms of m-and p-aminobenzoic acids participating in arylsulfonation of the acids with m-and p-nitrobenzenesulfonyl chlorides in the system water-2-propanol at 298 K at various water contents and pHs were estimated. The resulting data were used to estimate the rate constants for the reactions of the above forms with nitrobenzenesulfonyl chlorides, based on experimental kinetic data.
- Kustova,Kuritsyn,Khripkova
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- The through-bond interaction of a sulfur lone pair with oxygenated substituents in the thiacyclohexane framework
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Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C-OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6. CSIRO 2005.
- Andrau, Laura,White, Jonathan M.
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- Aryl sulfonic acid ammonium salt compound, preparation method and application thereof (by machine translation)
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The invention discloses a aryl sulfonic acid ammonium salt compound, preparation method and application thereof, the main process expressed as follows: formula (I) indicated by the aryl sulfonic acid compound crude product as raw material, in the solvent with the structural formula (II) shown in mixed organic amine, to form the structural formula (III) as shown by a aryl sulfonic acid ammonium salt; the resulting structural formula (III) aryl sulfonic acid ammonium salt shown by the alkali soluble acid or directly to obtain the acid of formula (I) shown in the purification of compounds such as aryl sulfonic acid. The invention is primarily embodied in the [...]: through the low quality aryl sulfonic acid compound refining, effectively reduces the content of harmful impurities, improve the quality of the aryl sulfonic acid compound, reducing the pressure of the downstream use, the process is stable. (by machine translation)
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Paragraph 0042; 0051
(2018/03/25)
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- Preparation method of aromatic sulfonic acid compound
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The invention discloses a preparation method of an aromatic sulfonic acid compound, and aims to provide the preparation method of the aromatic sulfonic acid compound, wherein the method is simple in process, low in equipment requirements, high in capacity, wide in raw material sources and small in environmental influence. The method is characterized by comprising the steps: with a starting material aromatic amine compound, dissolving in an acid, carrying out a diazotization reaction with sodium nitrite to prepare a diazocompound; carrying out a reaction of a catalyst cuprous salt with a thionyl chloride aqueous solution, and carrying out a sulfonylation reaction with the prepared diazocompound to obtain an aromatic sulfonyl chloride compound or an aromatic sulfonyl chloride hydrochloride compound, next hydrolyzing to obtain a crude product aromatic sulfonic acid compound, finally purifying through a beating way by an acidic solvent and an alcohol solution, and thus obtaining the high-purity aromatic sulfonic acid compound. The method is friendly to environment, has certain cost advantages, avoids use of more expensive aromatic thiol compounds as starting materials, and is beneficial for industrial production.
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Paragraph 0021; 0025
(2016/11/17)
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- Method for synthesizing p-nitrobenzenesulfonic
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The invention relates to a method for synthesizing p-nitrobenzenesulfonic and belongs to the technical field of organic chemical synthesis. The method comprises the steps of subjecting benzene serving as the raw material and sulfuric acid to sulfonation to obtain benzenesulfonic acid; pumping chlorine into benzenesulfonic acid, adding deionized water and zinc dibutyl dithiocaarbamate, and stirring the mixture; adding nitric acid and acetic anhydride into the mixture for water-bath heating, and then performing cooling through ice water; slowly adding a sodium hydroxide solution dropwise into the cooled mixture, performing heating reflux after dropping reaction, cooling the mixture to the room temperature, and obtaining p-nitrobenzenesulfonic through separation, recovery and drying. The method has the advantages that the reaction time is shortened by 30% of time needed by a 3-nitrobenzene acid synthesis method, pollution cannot be produced during reaction, and operation steps are simple.
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Paragraph 0008
(2016/10/07)
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- Synthesis method of 3-cloro-5-bromoaniline
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The invention discloses a synthesis method of 3-cloro-5-bromoaniline, and belongs to the technical field of organic synthesis. According to the method, benzenesulfonic acid is used as raw materials; firstly, concentrated nitric acid and a manganese dioxide catalyst are added for generating p-nitrobenzenesulphonic acid; then, NBS is added to generate 2-bromine p-nitrophenyl sulfonic acid; next, HCl is added for generating 2-cloro-6-bromine p-nitrophenyl sulfonic acid; next, a CH3COOH solution is added; benzenesulfonic acid in the 2-cloro-6-bromine p-nitrophenyl sulfonic acid is removed to obtain 3-cloro-5-bromonitrobenzene; finally, reducing Na2S and Zn are added for reduction, so that the 3-cloro-5-bromoaniline prepared by the method is obtained. Examples prove that the synthesis method has the advantages that the preparation is convenient and simple; the environment is protected; no pollution is caused; the equipment investment is low; any pollution does not exist; the yield reaches more than 85 percent.
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Paragraph 0013
(2017/01/23)
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- Nucleophilic Substitution Reactions of 2,4-Dinitrophenyl X-Substituted-Benzenesulfonates and Y-Substituted-Phenyl 4-Nitrobenzenesulfonates with Azide Ion: Regioselectivity and Reaction Mechanism
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The second-order rate constants for reactions of 2,4-dinitrophenyl X-substituted-benzenesulfonates (4a-4f) and Y-substituted-phenyl-4-nitrobenzenesulfonates (5a-5f) with N3- ion have been measured spectrophotometrically. The reactions of 4a-4f proceed through S-O and C-O bond fission pathways competitively. Fraction of the S-O bond fission decreases rapidly as the substituent X in the benzenesulfonyl moiety changes from an electron-withdrawing group to an electron-donating group. The Hammett plots for reactions of 4a-4f are linear with ρX=1.87 and 0.56 for the S-O and C-O bond fission, respectively. The fact that the substituent X is further away from the reaction site of the C-O bond fission than that of the S-O bond fission is one reason for the smaller ρX value. The nature of the reaction mechanism (i.e., a stepwise mechanism in which expulsion of the leaving group occurs after the rate-determining step) is also responsible for the smaller ρX value obtained from the C-O bond fission. The Bronsted-type plot for the reactions of 5a-5f is linear with βlg=-0.63, which is typical for reactions reported previously to proceed through a concerted mechanism. Effects of substituents X and Y on regioselectivity and reaction mechanism are discussed in detail.
- Moon, Ji-Hyun,Kim, Min-Young,Han, So-Yeop,Um, Ik-Hwan
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p. 1360 - 1365
(2015/07/15)
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- Synthesis of sulfonyl chlorides and sulfonic acids in SDS micelles
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H2O2/POCl3 is found to be a reactive reagent system that can be used in sodium dodecyl sulfate (SDS) micellar solution in aqueous media for the direct oxidative chlorination of thiol and di-sulfide derivatives to give the desired sulfonyl chlorides. The oxidation of thiols and disulfides to sulfonic acids with this system is also reported. In most cases, these reactions are highly selective, simple, and clean, affording products in excellent yields and high purity. Georg Thieme Verlag Stuttgart · New York.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Abbasi, Jamshid
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experimental part
p. 316 - 322
(2012/03/26)
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- Hydrates and ammonium salts of 4-nitrobenzenesulfonic acid: Supramolecular organization and its relation to proton conductivity
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Structural features, the crystal packing, and the proton conductivity of a series of hydrates and ammonium salts of 4-nitrobenzenesulfonic acid were studied. It was shown that infinite cation associates containing the onium moiety are responsible for a substantial increase in the proton conductivity. The nature of the disorder in a series of crystals was investigated by performing X-ray diffraction studies at different temperatures. A new type of structural synthons, viz., anion-anion dimers stabilized by the SO3 -.NO2 interaction, was found and characterized and the role of solvent water molecules was elucidated based on high-resolution X-ray diffraction data. The water molecules serve mainly as channels for charge transfer from the cation to the anion with retention of the electroneutrality.
- Barzilovich,Lyssenko,Antipin,Aldoshin
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experimental part
p. 1185 - 1195
(2012/06/16)
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- Photoacid generators (PAGs) based on N-acyl-N-phenylhydroxylamines for carboxylic and sulfonic acids
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Simple and efficient photoacid generators (PAGs) for carboxylic and sulfonic acids based on N-acyl-N-phenylhydroxylamines have been demonstrated. Irradiation of o-carboxylates and thermally rearranged o-arenesulfonates of N-acyl-N-phenylhydroxylamines using UV light (≥254 nm) in aqueous methanolic solution resulted in efficient generation of carboxylic and sulfonic acids, respectively. The carboxylic acid generation ability of N-acyl-N- phenylhydroxylamines was found to be dependent on their N-acyl substituents. Further, polymer bearing o-arenesulfonates of N-acyl-N-phenylhydroxylamine was synthesized and demonstrated as PAG for sulfonic acids.
- Ikbal, Mohammed,Jana, Avijit,Singh, N.D. Pradeep,Banerjee, Rakesh,Dhara, Dibakar
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p. 3733 - 3742
(2011/06/21)
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- Design and mechanism of iron catalyzed carbon-carbon bond cleavage and N-oxidation processes of hazardous dyes for selective synthesis of nitroarenes and aminoarenecarboxylic acids
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An efficient iron catalyzed oxidative degradation process has been developed for selective conversion of environmentally hazardous azo and indigo dyes into nitroarenes and aminoarenecarboxylic acids (anthranilic acids) respectively, using polymer supported tribromide reagent at an alkaline pH. The in situ generated and the isolated (defined) chloro-iron(II)-terpyridine- pyridine carboxylate [Fe(tpy)(pic)Cl] catalyst system has been developed and its catalytic function was invented for the degradation process. The different nitrogenous and oxygen ligands have been screened out for the development of best catalyst system, and eventually we explored pyridine 2-carboxylic acid and terpyridine ligands together, were found to be the best. Notably, the in situ generated and the defined catalyst systems have found to be more effective with similar catalytic activities towards the oxidative degradation of both the dyes. As a result, the whole oxidative degradation process has been carried out with Fe(tpy)(pic)Cl catalyst system and the general process utilizes the efficient catalytic method for the selective oxidation of -NN- and -CC- bonds of azo and indigo dyes respectively. The detailed catalysis, mechanistic and kinetic investigations have been made for the reactions. Interestingly, both the dyes proceed with a common oxidative degradation mechanism under identical kinetic patters. A common oxidative degradation mechanism which operates in both the dyes has been proposed and an identical related kinetic model was designed. The main interesting aspect of the present work pertains to the catalytic conversion of environmentally hazardous compounds into useful molecules; such are anthranilic acids and nitrobenzenes. Other special aspect related to catalytic activity of iron and potentially, iron catalyst accelerates the reaction rates with 15-20-fold faster. The reactions were also carried out with different polymer supported trihalide and inter-halide reagents. Notably, trichloride and inter-halide regents were found to be more reactive. The catalytic method developed for the degradation process was found to be very efficient and the involvement of cost-effective reagents makes the reaction simple, and can be conveniently scalable to industrial/technological operations with suitable modifications.
- Jagadeesh, Rajenahally V.,Kiran,Bhagat, Pundlik R.,Kumar, S. Senthil,Nithya,Khan, F. Nawaz,Sivakumar
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experimental part
p. 92 - 104
(2011/05/05)
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- Selective oxidation reactions of diaryl- and dialkyldisulfides to sulfonic acids by CH3ReO3/hydrogen peroxide
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Diaryl- and dialkyl disulfides were oxidized in acetonitrile at 20 °C by CH3ReO3/H2O2 oxidant system to yield selectively the corresponding sulfonic acids in short reaction times and in high yields.
- Ballistreri, Francesco P.,Tomaselli, Gaetano A.,Toscano, Rosa M.
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experimental part
p. 6231 - 6232
(2010/01/11)
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- The SN3-SN2 spectrum. Rate constants and product selectivities for solvolyses of benzenesulfonyl chlorides in aqueous alcohols
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Rate constants for a wide range of binary aqueous mixtures and product selectivities (S) in ethanol - Water (EW) and methanol-water (MW) mixtures, are reported at 25 °C for solvolyses of benzenesulfonyl chloride and the 4-chloro - Derivative. S is defined as follows using molar concentrations: S =([ester product]/[acid product]) × ([water solvent]/[alcohol solvent]). Additional selectivity data are reported for solvolyses of 4-Z-substituted sulfonyl chlorides (Z - OMe, Me, H, Cl and NO2) in 2, 2, 2-trifluoroethanol-water. To explain these results and previously published data on kinetic solvent isotope effects (KSIEs) and on other solvolyses of 4-nitro and 4-methoxybenzenesulfonyl chloride, a mechanistic spectrum involving a change from third order to second order is proposed. The molecularity of these reactions is discussed, along with new term 'SN3-SN2 spectrum' and its connection with the better established term 'S N2-SN1 spectrum'. Copyright
- Bentley, T. William,Jones, Robert O,Kang, Dae Ho,Koo, Sun
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scheme or table
p. 799 - 806
(2010/06/16)
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- Selective and mild oxidation of thiols to sulfonic acids by hydrogen peroxide catalyzed by methyltrioxorhenium
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Aromatic and aliphatic thiols are oxidized in acetonitrile at 20 °C by hydrogen peroxide in the presence of methyltrioxorhenium as the catalyst to yield the corresponding sulfonic acids in high isolated yields (85-94%).
- Ballistreri, Francesco P.,Tomaselli, Gaetano A.,Toscano, Rosa M.
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p. 3291 - 3293
(2008/09/20)
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- Regio- and chemoselective enzymatic N-oxygenation in vivo, in vitro, and in flow
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(Chemical Equation Presented) Action by the para: Evaluation of the nitro-group-forming N-oxygenase AurF in vivo, in vitro, and immobilized as a fusion protein with simply H2O2 as oxidant (peroxide shunt) reveals para-regioselective oxygenation of aromatic amines (see scheme). This effect includes the selective oxygenation of diamino compounds.
- Winkler, Robert,Richter, Martin E. A.,Knuepfer, Uwe,Merten, Dirk,Hertweck, Christian
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p. 8016 - 8018
(2007/10/03)
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- Effect of Amine Nature on Reaction Rate and Mechanism in Nucleophilic Substitution Reactions of 2,4-Dinitrophenyl X-Substituted Benzenesulfonates with Alicyclic Secondary Amines
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Second-order rate constants have been measured for reactions of 2,4-dinitrophenyl X-substituted benzenesulfonates with a series of alicyclic secondary amines. The reaction proceeds through S-O and C-O bond fission pathways competitively. The S-O bond fission occurs more dominantly as the amine basicity increases and the substituent X in the sulfonyl moiety becomes more strongly electron withdrawing, indicating that the regioselectivity is governed by the amine basicity as well as the electronic nature of the substituent X. The S-O bond fission proceeds through an addition intermediate with a change in the rate-determining step at pKa° = 9.1. The secondary amines are more reactive than primary amines of similar basicity for the S-O bond fission. The k1 value has been determined to be larger for reactions with secondary amines than with primary amines of similar basicity, which fully accounts for their higher reactivity. The second-order rate constants for the S-O bond fission result in linear Yukawa-Tsuno plots while those for the C-O bond fission exhibit poor correlation with the electronic nature of the substituent X. The distance effect and the nature of reaction mechanism have been suggested to be responsible for the poor correlation for the C-O bond fission pathway.
- Um, Ik-Hwan,Chun, Sun-Mee,Chae, Ok-Mi,Fujio, Mizue,Tsuno, Yuho
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p. 3166 - 3172
(2007/10/03)
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- Competitive Reaction Pathways in the Nucleophilic Substitution Reactions of Aryl Benzenesulfonates with Benzylamines in Acetonitrile
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The reactions of aryl benzenesulfonates (YC6H4SO2OC6H4Z) with benzylamines (XC6H4CH2NH2) in acetonitrile at 65.0 deg C have been studied. The reactons proceed competitevely by S-O (kS-O) and C-O (kC-O) bond scission, but the former provides the major reaction pathway. On the basis of analysis of the Hammet and Broensted coefficients together with the cross-interaction constants ρXY, ρYZ, and ρXZ, stepwise mechanisms are proposed in which the S-O bond cleavage proceeds by rate-limiting formation of a trigonal-bipyramidal pentacoordinate (TBP-5C) intermediate, whereas the C-O bond scission takes place by rate-limiting expulsion of the sulfonate anion (YC6H4SO3-) from a Meisenheimer-type complex.
- Choi, Jin Heui,Lee, Byung Choon,Lee, Hai Whang,Lee, Ikchoon
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p. 1277 - 1281
(2007/10/03)
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- Aminopiperidine derivates as integrin αvβ3 antagonists
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An objective of the present invention is to provide compounds having integrin αvβ3antagonistic activity, cell adhesion inhibitory activity, GP IIb/IIIa antagonistic activity, and/or human platelet aggregation inhibitory activity, and, therapeutic agents for treating cardiovascular diseases, angiogenesis-related diseases, cerebrovascular diseases and the like and for inhibiting platelet aggregation. The derivatives according to the present invention are compounds represented by formula (I) or pharmaceutically acceptable salts or solvates thereof: wherein A represents a five- to seven-membered heterocyclic group containing two nitrogen atoms or the like; D represents >NH2, >CH2or the like; X and Z represent CH or a nitrogen atom; R7and R8represent alkyl, halogen or the like; Q represents >C═O, >CH2or the like; R9represents H, alkyl, aralkyl or the like; R10represents H, alkynyl or the like; R11represents H, substituted amino or the like; R12represents H or alkyl; m is 0 to 5; n is 0 to 4; p and q are each 1 to 3; and r is 0 or 1.
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- Exploiting differences in solution vs solid-supported reactivity for the synthesis of sulfonic acid derivatives
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(matrix presented) Quantitative We describe a method herein for the protection of aryl and alkyl sulfonates during synthesis which employs commercially available Wang or MBOH resin, both of which terminate as benzyl alcohols, as both a protecting group and "traceless" linker. Given the known instability of benzylic sulfonate esters to nucleophilic displacement in solution, this linkage is surprisingly stable: no loss of either aryl or alkyl sulfonates is observed when the resin is exposed to a wide variety of organic bases and solvents at room temperature. Further elaboration of the resin-bound sulfonates via Suzuki coupling is also described.
- Hari, Anitha,Miller, Benjamin L.
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p. 2109 - 2111
(2008/02/10)
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- Effect of aqueous-organic solvent on the kinetics of acylation of arylhydrazides with aromatic sulfonic acid chlorides
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The kinetics of acylation of benzoic and m-bromobenzoic hydrazides with 4-nitrobenzenesulfonyl chloride in water-isopropanol, as well as of benzoic and benzenesulfonic hydrazides with 3-nitrobenzenesulfonyl chloride in water-dioxane at 298 K were studied. Increased water contents in the binary solvents favor faster reactions. At initial reactant concentrations of 0.1-0.5 M, water-isopropanol and water-dioxane mixtures with high water contents (40-70 wt%) can be used as media for preparing acylation products in 98-99.5% yield.
- Kustova,Kuritsyn
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p. 280 - 282
(2007/10/03)
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- Reactivity of sterically hindered aromatic sulfonic acid derivatives: VII.* hydrolysis of arenesulfonyl chlorides in aqueous acetonitrile
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Hydrolysis of sterically hindered arenesulfonyl chlorides in aqueous acetonitrile is accelerated by both electron-acceptor and some electron-donor substituents in the benzene ring. A multifactor kinetic model of the process is proposed. 1998 MAHK Hayka/Interperiodica Publishing.
- Rubleva,Krut'ko,Mitchenko
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p. 1006 - 1009
(2007/10/03)
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- Oxidative hydrolysis of phosphorus(V) esters of thiols by peroxymonosulfate ion. Reactions of peroxymonosulfate ion with phosphorus(V) esters of thiols
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Peroxymonosulfate ion, HSO5-, as Oxone, readily converts phosphorus(V) esters of thiols into the phosphorus(V) and sulfonic acids. The esters were Ph2PO·SC6H4R(p) with R=MeO (1a), Me (1b), H (1c), Cl (1d) and NO2 (1e), (EtO)2PO·SPh (2), Ph2OI·SEt (3) and PhPO(OEt)SEt (4). Reactions are first order in each reactant and second-order rate constants, k2, for 1a-e fit the Hammett equation with ρ=-0.46. The rate constants increase markedly with increasing water content of H2O-MeCN, the activation enthalpies are low and the entropies are negative. Despite the low value of -ρ, these esters are much less reactive than thiol ethers, but the rate constants of reactions of these compounds and acyl thiols qualitatively follow the ionization potentials of the ethers and the esters.
- Blasko, Andrei,Bunton, Clifford A.,Kumar, Anurag
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p. 427 - 434
(2007/10/03)
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- Kinetics and mechanism of the aminolysis of cycloalkylmethyl arenesulfonates
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Nucleophilic substitution reactions of cycloalkylmethyl arenesulfonates (CmH2n-1 CH2OSO2C6H4Z) with anilines (XC6H4NH2) in methanol at 65.0 °C were studied. The reactivity order (n=4>6>7>5) reflects largely the order of steric effect of the ring size (SEs term) except for n=5, which exhibits the least reactivity. This reversal of the order for n=5 is considered to result from large rate retardation due to polar effect of the ρ*σ* term. Application of the Taft equation to the rate data for n=5 and 6 gives ρ=17·4 and 5=2·3 with correlation coefficient of 0·90. The σ* values for n=4 and 7 are estimated to be - 0·23 and - 0·11, respectively. The positive ρxz values of ca 0·3 are consistent with previous results for the reactions at primary reaction centers.
- Oh, Hyuck Keun,Song, Se Jeong,Jo, Dong-Soo,Lee, Ikchoon
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- Synthesis of 3-chloro-Δ3-cephem-4-carboxylate by addition/cyclization of allenecarboxylate. Copper(II)-promoted aerobic oxidation of arenesulfinic acids
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The selective transformation of allenecarboxylate derived from penicillin into 3-chloro-Δ3-cephem-4-carboxylate was successfully achieved by an addition/cyclization reaction with chloride salts in aerobic media containing a copper(II) catalyst, in which copper(II)-catalyzed aerobic oxidation of in situ generated benzenesulfinate ion into less nucleophilic sulfonate ion prior to the nucleophilic addition of the former ion to the allenecarboxylate would completely eliminate the formation of undesired 3-phenylsulfonyl-Δ3-cephem-4-carboxylate. Under similar aerobic conditions, arenesulfinates salts and arenesulfinic acids were smoothly oxidized to the corresponding sulfonate salts and sulfonic acids, respectively.
- Tanaka, Hideo,Kikuchi, Ryo,Torii, Sigeru
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p. 1391 - 1396
(2007/10/03)
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- Quantitative treatment of micellar effects upon nucleophilic substitution
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Cationic micelles of cetyltrimethylammonium surfactants increase first-order rate constants for the basic hydrolysis of tert-butyl perbenzoate and 2-naphthyl benzoate.Dealkylation of both butyl 4-nitrobenzenesulfonate and butyl 4-bromobenzenesulfonate by halide ions in micelles of CTACl, CTABr and CTAOMs, and by azide ion in micelles of cetyltrimethylammonium mesylate (CTAOMs) have been examined.The nucleophilic aromatic substitutions of 2-chloro-3,5-dinitropyridine by OH- and N3- ions in the presence of CTABr, CTACl and CTAOMs micelles have also been examined.The rate enhancements have been treated in terms of concentration of both substrates and nucleophilic anions at the micellar surface.The anionic concentrations depend upon specific and non-specific coulombic interactions, which were calculated by solving the Poisson-Boltzmann equation (PBE).The same parameters were used in fitting data for reactions of N3-, Br- or Cl- as nucleophiles and for systems with Cl-, Br- and OMs- as inert counter-anions in CTACl, CTABr and CTAOMs, respectively.
- Al-Lohedan, Hamad A.
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p. 1707 - 1714
(2007/10/02)
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- Sulfide Oxidation and Oxidative Hydrolysis of Thioesters by Peroxymonosulfate Ion
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Peroxymonosulfate ion, HSO5-, as OXONE, in aqueous MeCN readily converts aryl thiobenzoates, XC6H4CO*SC6H4Z (X = p-OMe, p-Me, H, p-Cl, p-CN; Z = p-OMe, p-Me, H, m-OMe, p-Cl, m-Cl, p-NO2) into carboxylic and sulfonic acids.Reactions are second order and have small substituent effects, with ρ ca. -0.6 based on ?m and ?p substituent parameters, but rates increase markedly with increasing water content in aqueous MeCN and entropies of activation are negative.The initial step is very similar to the oxidation of methyl aryl sulfides by HSO5- which has similar solvent and substituent effects.Enthalpies of activation are much lower for oxidation of the sulfides than of the corresponding esters but entropies of activation are similar.
- Bunton, Clifford A.,Foroudian, Houshang J.,Kumar, Anurag
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- Stoichiometric Solvation Effects. Part 2. A New Product-Rate Correlation for Solvolyses of p-Nitrobenzenesulfonyl Chloride in Alcohol-Water Mixtures
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For reactions involving nucleophilic attack in alcohol-water mixtures, a linear relationship between the reciprocal of product selectivities (S) and the molar ratios of alcohol and water solvents can be derived, if it is assumed that the reactions are second-order in protic solvent (e.g., with one molecule of solvent acting as a nucleophile and the other as a general base).The relationship (1/S = (slope)(/) + intercept) fits the products of solvolyses of p-nitrobenzenesulfonyl chloride in aqueous ethanol and methanol at 25 deg C (determined by refrigerated RP-HPLC) within the range from water to 80percent v/v alcohol-water.From the slopes and intercepts of these product plots and the one observed rate constant for hydrolysis in pure water, the observed first-order rate constants in alcohol-water mixtures up to 90percent (v/v) can be calculated satisfactority, further supporting the validity of the derived linear relationship; the kinetic model includes three thrid-order rate constants: kww, where water acts as both nucleophile and general base; kwa, water acts as a nucleophile and alcohol acts as a general base; kaw, alcohol acts as a nucleophile and water acts as a general base.Inclusion of a fourth rate-constant, kaa, where the alcohol acts as a nucleophile and a second molecule of alcohol acts as a general base, is necessary to account for solvolyses in 90-99percent alcohol-water; kaa can be calculated from the observed first-order rate constants in pure alcohols.Independent values of kaw and kwa can be obtained from kaa and the slopes and intercepts of linear relationships between S and the molar solvent ratio / within the range 90-99percent alcohol-water.The dominant effect of solvent stoichiometry and the absence of other substantial medium effects is confirmed by the approximately constant third-order rate constants, calculated from the observed first-order rate constants in acetonitrile-, acetone- and dioxane-water mixtures.
- Bentley, T. William,Jones, Robert O.,Koo, In Sun
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p. 753 - 760
(2007/10/02)
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- Process of preparing enriched enantiomers of glycerol carbonate and derivatives thereof for synthesis of β-blockers
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Enriched enantiomers of glycerol Carbonate are produced under the influence of a hydrolytic enzyme, either by selective esterification of racemic glycerol carbonate or by selective hydrolysis of an ester of the racemate. The enriched enantiomeric product is readily converted to starting materials and intermediates useful in the synthesis of enantiomerically pure therapeutic agents, such as β-adrenergic blockers.
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- Solvolysis Mechanism of Indan-2-yl Arenesulfonates
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The solvolysis rates of 5-(Y)-substituted indan-2-yl (Z)-benzenesulfonates were determined in a variety of protic solvents at 45.0, 55.0 and 65.0 deg C.Application of an extended Grunwald-Winstein equation indicates that kinetic responses to both solvent ionizing power, YOTs, and solvent nucleophilicity, NOTs, are relatively low but increase in parallel with increasing leaving ability, m = 0.39-0.46 and I=0.32-0.41 for Z=p-Me p-NO2.The magnitude of cross-interaction constant, ρYZ, is also relatively small (0.16-0.32), which is, however, much more dependent on the nucleophilicity rather than the ionizing power of the solvent.These are consistent with the typical SN2 mechanism proceeding through a transition state in which solvent participates in both bond-making and -breaking processes.
- Lee, Ikchoon,Lee, Young Sook,Lee, Bon-Su,Lee, Hai Whang
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p. 1441 - 1445
(2007/10/02)
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- Cross-interaction Constants as a Measure of the Transition State Structure. Part 11. Solvolyses of 1-Phenyl-2-propyl Benzenesulphonates
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The solvolyses of 1-phenyl-2-propyl benzenesulphonates (PPBs) have been investigated in methanol-acetonitrile mixtures and in hexafluoropropan-2-ol (HFIP).The transition state structure has been discussed using various selectivity parameters, especially with the cross-interaction constants, ρYZ and λYZ, between substituents in the substrate (Y) and in the leaving group (Z).It has been found that the solvolysis proceeds by the solvent-assisted pathway, ks, in methanol, whereas in HFIP PPBs solvolyse via the aryl-assisted pathway, kΔ.The only exception was the p-MeO substituent, which deviates positively in methanol from the log ks vs. ? plot due to participation of the aryl-assisted path and negatively in HFIP from the log kΔ vs. ?(neophyl) plot due to deactivation by hydrogen bonding of the methoxy oxygen in the acidic solvent.The two distinctive high values of ρYZ provided evidence for the strongly bound transition states in the two processes, ks and kΔ, with a relatively low degree of bond breaking.
- Lee, Ikchoon,Lee, Won Heui,Lee, Hai Whang,Lee, Byung Choon
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p. 785 - 791
(2007/10/02)
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- REACTIVITY OF STERICALLY HINDERED DERIVATIVES OF AROMATIC SULFONIC ACIDS II. EFFECTS OF SUBSTRATE STRUCTURE AND MEDIUM POLARITY ON THE HYDROLYSIS OF BENZENESULFONYL CHLORIDES
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The kinetics of the hydrolysis of substituted benzenesulfonyl chlorides XArSO2ClN2 mechanism.
- Vizgert, R. V.,Rubleva, L. I.,Maksimenko, N. N.
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p. 2259 - 2262
(2007/10/02)
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- Cross Interaction Constants As a Measure of Transition State structure. Part 7. Aminolysis of Alkyl Benzenesulphonates
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Kinetic studies of the reactions of methyl and ethyl benzenesulphonates with anilines and benzylamines in methanol and acetonitrile at 65.0 deg C have been reported.The magnitudes of cross-interaction constants between substituents in the nucleophile (X) and the leaving group (Z),ρxz and βxz, were found to be greater for the ethyl series which indicates a tighter transition state for ethyl rather than methyl derivatives.This unexpected trend has been rationalized by making the assumption that the small electron-donating polar effect, of the α-methyl substituent in the ethyl compounds, requires a tighter transition-state structure in addition to the major effect of steric repulsion on the activation barrier which is present in all SN2 reactions taking place at a carbon centre.
- Lee, Ikchoon,Choi, Young Hoon,Rhyu, Keun Woo,Shim, Chang Sub
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p. 1881 - 1886
(2007/10/02)
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- REACTIVITY OF STERICALLY HINDERED DERIVATIVES OF AROMATIC SULFONIC ACIDS. I. EFFECT OF SUBSTITUENTS ON RATE AND MECHANISM OF HYDROLYSIS OF SOME SUBSTITUTED BENZENESULFONYL CHLORIDES
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The kinetics of the hydrolysis of substituted benzenesulfonyl chlorides XArSO2Cl in 70percent aqueous dioxane at 303, 313, and 323 K were studied by acid-base titration.The effect of the investigated set of substituents cannot be described by a single linear relationship of the Hammett type.The substrates containing methyl groups at the ortho positions of the aromatic ring exhibit enhanced reactivity.The effect of the structural changes in the sulfonyl chlorides on the nature of bond formation and cleavage in the transition state is discussed in terms of the SN2 mechanism.An attempt is made to explain the V-shaped form of the relationship between log k and ? from the standpoint of the hyperconjugation effect, the contribution from which amounts to about 10percent of the ρ value.
- Vizgert, R. V.,Rubleva, L. I.,Maksimenko, N. N.
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p. 727 - 730
(2007/10/02)
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- Multiple Structure-Reactivity Relationships for a Menschutkin-type SN2 Reaction
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The mechanism of nucleophilic displacement was studied by using three variable systems of ρX, ρY and ρZ obtained from the change of substituents X, Y and Z for the reaction of (Z)-substituted benzyl (X)-benzenesulphonates with (Y)-substituted N,N-dimethylanilines in aceton at 35 deg C.The coefficient of the interaction term, ρXY, has a value of 0.21 which means that bond-making and -breaking are concerted in the SN2 transition state.In the range Z = H to p-NO2, in which the SN2 mechanism is predicted to be dominant, the ρZY value is very large, 0.5, which means that the interaction between Z and Y is very large. ρZX is ca. 0.06 which means that the interaction is small between X and Z.In contrast, in the range Z = H to p-Me, in which the SN1 mechanism is dominant, the ρZY value is nearly zero, indicating no interaction between Z and Y.Changes of substituent effect and interaction terms, ρXY, ρYZ and ρZX are useful tools for distinguishing wrong reaction mechanisms.
- Yoh, Soo-Dong,Tsuno, Yuho,Fujio, Mizue,Sawada, Masami,Yukawa, Yasuhide
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- Kinetics and Mechanism of Reactions between 2-Phenylethyl Benzenesulphonates and Anilines in Methanol
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Kinetics of reactions between 2-phenylethyl benzenesulphonates and anilines in methanol at 65.0 deg C have been studied; the mechanism is discussed on the basis of cross interaction constants, ρij.The overall reaction was found to proceed by a dissociative SN2 mechanism with a relatively small degree of aryl participation.The fraction of the phenonium ion intermediate captured by the nucleophile, aniline, in the aryl-assisted pathway has been shown to increase with a stronger nucleophile, and a four-centre transition state in an intermolecular SNi mechanism is suggested for the aryl-unassisted pathway.
- Lee, Ikchoon,Choi, Yong Hoon,Lee, Hai Whang,Lee, Byung Choon
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p. 1537 - 1540
(2007/10/02)
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- KINETICS AND MECHANISM OF HYDROLYSIS OF AROMATIC SULFONYL CHLORIDES IN AQUEOUS SULFURIC ACID SOLUTIONS
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The kinetics of the hydrolysis of 12 aromatic sulfonyl chlorides were studied by a spectrophotometric method in water and aqueous sulfuric acid solutions ( 1.0 - 60.5 wt.percent ) at 25 deg C and in 50percent sulfuric acid at several temperatures.It was shown that the reaction obeys the single-parameter equation log keff = log k0 + m'X, in which keff and k0 are the first-order rate constants in a solution with "excess acidity" X and in water respectively.The coefficient m' depends on the substituent in the ring and is equal to -0.85 to -0.38.The activity of the water does not enter into the equation for the calculation of keff.For the hydrolysis of nine substituted sulfonyl chlorides in 50percent sulfuric acid a satisfactory correlation is observed between log keff and the Σ?0.Palm induction constants ( ρ = -1.85 +/- 0.12 ).A reaction mechanism is proposed in which the rate-determining stage in the hydrolysis of the ArSO2Cl is the transformation of the complex H2O...SO2(Cl)Ar, in the form of which all the sulfonyl chloride dissolved in the water is present, into the reaction products.
- Gnedin, B. G.,Ivanov, S. N.,Shchukina, M. V.
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p. 731 - 737
(2007/10/02)
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- Structural Effects on the Transition States of Imine-Forming Eliminations in N-Substituted O-(Arylsulfonyl)hydroxylamines
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A series of amines with various alkyl and aryl substituents at C-1 were converted to the corresponding N-(arylsulfonoxy)amines, which served as precursors for base-promoted, imine-forming elimination.By varying the bases used to promote the elimination and by varying the leaving groups attached to nitrogen, the Broensted parameters β and βlgCH3 were determined.These were used to locate the transition state on the More O'Ferrall-Jencks energy surface for elimination.Substituents were found to influence the structure of the activated complex markedly.Resonance effects were most important, while inductive effects had little influence .
- Hoffman, Robert V.,Shankweiler, Jean M.
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p. 4019 - 4022
(2007/10/02)
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- Kinetics of hydrolysis of aromatic mono- and disulfonyl chlorides
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A continuous polarografic method of recording instantaneous concentrations of - SO2Cl groups in an aqueous acetic acid system containing CH3CO2Na has been elaborated.Ten model monosulfonyl chlorides underwent hydrolysis according to pseudo-first order kinetics (20percent H2O, 80percent v.v.CH3CO2H, 0.5 mol/dm3 CH3CO2Na).Plots of hydrolysis for seven disulfonyl dichlorides with different number of - CH3 groups have been determined.Pseudo-first order rate constants for two consecutive reactions of hydrolysis (k1 and k2) have been computed and the influence of -SO2Cl and -SO3- groups on the reactivity of the second group - SO2Cl has been discussed.The mechanism of nucleophilic substitution has also been discussed.
- Sanecki, Przemyslaw,Rokaszewski, Edward
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p. 2263 - 2267
(2007/10/02)
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- EFFECT OF STRUCTURE ON THE KINETICS AND MECHANISM OF THE ACID-CATALYZED DECOMPOSITION OF N-ALKYL-N-NITROBENZENESULFONAMIDES
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The decomposition rate of a series of meta- and para-substituted N-alkyl-N-nitrobenzenesufonamides was determined by a spectrophotometric method in aqueous sulfuric acid.It was shown that the decomposition of the compounds takes place both by denitration and by cleavage of the N-S bond with the formation fo primary aliphatic N-nitrosamines.Electron-withdrawing substituents in the aromatic ring shift the process toward denitration.
- Drozdova, O. A.,Astrat'ev, A. A.,Kuznetsov, L. L.,Selivanov, V. F.
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p. 671 - 675
(2007/10/02)
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- EFFECT OF STRUCTURE ON THE KINETICS AND MECHANISM OF THE ACID-CATALYZED DECOMPOSITION OF N-NITROBENZENESULFONAMIDES
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The decomposition rate of a series of ring-substituted N-nitrobenzenesulfonamides in aqueous sulfuric acid was measure by a spectrophotometric method.Decomposition of the compounds takes place both by the cleavage of the N-S bond to form the corresponding sulfonic acid, nitrous oxide, and water and by denitration.In crease in the electronegativity of the substituent in the aromatic ring promotes the denitration reaction.
- Drozdova, O. A.,Astrat'ev, A. A.,Kuznetsov, L. L.,Selivanov, V. F.
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p. 2063 - 2067
(2007/10/02)
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- REACTION OF AROMATIC COMPOUNDS WITH NUCLEOPHILIC REAGENTS IN LIQUID AMMONIA. II. NUCLEOPHILIC SUBSTITUTION IN NITROHALOGENO AND POLYFLUORINATED AROMATIC COMPOUNDS
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The possibility of aromatic nucleophilic substitution in liquid ammonia was investigated for the case of the reaction of p-nitrochlorobenzene, 2,4-dinitrochlorobenzene, hexafluorobenzene, bromopentafluorobenzene, pentafluorobenzene, and octafluoronaphthalene with a series of charged nucleophiles (potassium hydroxide and sulphite, alcoholates, sodium azide, thiophenolate, phenolate, and sulfide) at -70 to -33 deg C.It was shown that alkyl ethers of p-nitrophenol, phenyl p-nitrophenyl sulfide, 2,4-dinitrophenyl azide, polyfluorinaqted phenols, and their ethers can be obtained with good yields.Comparisons of the results with published data on the rate of the same reactions in other solvents shows that liquid ammonia is highly effective as a solvent for aromatic nucleophilic substitution reactions and in some cases makes it possible to avoid side processes.
- Shtark, A. V.,Kizner, T. A.,Shteingarts, V. D.
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p. 2051 - 2056
(2007/10/02)
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