- One-pot synthesis of 6-bromo-4,4-dimethylthiochroman
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One-pot synthesis of 6-bromo-4,4-dimethylthiochroman from bromobenzene is reported. The crucial connection between the three steps is that the byproducts in the first two steps are used as the catalyst in the third step. Compared with the previous route, this approach is of low consumption and low pollution.
- Zhou, Shaodong,Liao, Zutai,Yuan, Jixin,Qian, Chao,Chen, Xinzhi
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Read Online
- Oxidative cleavage of S-Arylmercaptoacetic acids by pyridinium chlorochromate: Kinetic and correlation analysis
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Kinetics of oxidation of 24 S-Arylmercaptoacetic acids (SAMA) by pyridinium chlorochromate (PCC) have been studied in acid medium. The product of oxidation is the corresponding thiophenol. The rate data of meta- and para-substituted acids have been correlated well with σI, σ°R values and the meta-compounds correlate well with F,R values. The reaction constants are negative and of smaller magnitudes. Further, the ortho-substituted acids show a good correlation with triparametric equation involving Taft's σI and σ°R and charton's steric parameter v. There is no considerable steric contribution to the total orthosubstituent effect. Based on these observations, the mechanism involving the formation of protonated arylsulfinylacetic acid intermediate, followed by an intramolecular rearrangement leading to the product thiophenol has been proposed.
- Kabilan,Girija,Rajagopal
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Read Online
- 2-(3-Cyanopropyldimethylsilyl)ethyl as a Polar Sulfur Protecting Group
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Organosulfur compounds are ubiquitous in synthetic chemistry, biology and materials chemistry. The reactivity of free sulfhydryls requires their masking in many synthetic strategies. To facilitate the isolation of protected thiols by chromatography, we propose 2-(3-cyanopropyldimethylsilyl)ethyl as a polar protecting group analogue of 2-(trimethylsilyl)ethyl. The masked thiophenol is obtained in two synthetically complementing ways. Either an existing thiophenol is protected, or the protected thiol group is introduced by a cross-coupling reaction. In both cases the required reagents are readily available from inexpensive starting materials. Thiol protection and thiol introduction both tolerate a large variety of functional groups and substitution patterns, and the protected thiophenols are stable toward a broad range of reaction conditions. The stability of the protected derivatives in cross-coupling reactions and the mild reaction conditions for the release of the protecting group further emphasizes the potential of the methodology.
- Bannwart, Linda M.,Mayor, Marcel,Rieder, Pascal S.
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Read Online
- SINGLE-STEP SYNTHESIS METHOD OF ARYL THIOL AND APPLICATION THEREOF
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The present invention relates to a single-step synthesis method of aryl thiol, and more specifically, to a method of synthesizing aryl thiol in a single-step by making aryl halide react with alkane dithiol in the presence of a transition metal catalyst. According to the present invention, a single-step synthesis method using the transition metal catalyst, the synthesis method which is capable of synthesizing aryl thiol from aryl halide at a high yield, can be provided. Various aryl halides may be applied to the synthesis method. Further, the synthesis method has advantages that an easily usable reagent may be used, operations are simple, and reactions can be performed under mild conditions. In addition, the synthesized aryl thiol may be used in the synthesis of advanced molecules such as diaryl sulfides and benzothiophenes.COPYRIGHT KIPO 2017
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Paragraph 0032; 0033; 0063; 0067; 0069; 0070
(2017/09/02)
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- Copper(II)-Catalyzed Single-Step Synthesis of Aryl Thiols from Aryl Halides and 1,2-Ethanedithiol
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A highly efficient transition metal-catalyzed single-step synthesis of aryl thiols from aryl halides has been developed employing copper(II) catalyst and 1,2-ethanedithiol. The key features are use of readily available reagents, a simple operation, and relatively mild reaction conditions. This new protocol shows a broad substrate scope with excellent functional group compatibility. A variety of aryl thiols are directly prepared from aryl halides in high yields. Furthermore, the aryl thiols are used in situ for the synthesis of more advanced molecules such as diaryl sulfides and benzothiophenes.
- Liu, Yajun,Kim, Jihye,Seo, Heesun,Park, Sunghyouk,Chae, Junghyun
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supporting information
p. 2205 - 2212
(2015/07/27)
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- The Chan-Lam reaction of chalcogen elements leading to aryl chalcogenides
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A copper-catalyzed chalcogenation of arylboronic acids with elemental sulfur or selenium is established, which provides diaryl disulfides or diaryl monoselenides in moderate to good yields with excellent selectivities, respectively. Moreover, after sequential reduction and coupling with aryl/alkyl iodides in one pot, unsymmetrical monosulfides were obtained in good yields.
- Yu, Jin-Tao,Guo, Huan,Yi, Yuanqiuqiang,Fei, Haiyang,Jiang, Yan
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supporting information
p. 749 - 752
(2014/04/03)
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- Novel one-pot synthesis of thiophenols from related triazenes under mild conditions
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In this work, at first, triazenes were synthesized from primary aryl amines. Afterwards, triazenes were converted into the corresponding thiophenols in one-pot using sodium sulfide in acidic media, by in situ generation of diazonium counterion beside hydrogen sulfide as anionic sulfur nucleophile at room temperature. The procedure can be a convenient shortcut for the preparation of thiophenols from primary aryl amines. Georg Thieme Verlag Stuttgart · New York.
- Khazaei, Ardeshir,Kazem-Rostami, Masoud,Moosavi-Zare, Ahmadreza,Bayat, Mohammad,Saednia, Shahnaz
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experimental part
p. 1893 - 1896
(2012/09/22)
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- Catalytic transfer hydrogenation of aryl sulfo compounds
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A new method to reduce aryl sulfo compounds via transfer hydrogenation was investigated, using Pd/C as a catalyst, and 2-propanol or formic acid as hydrogen sources. This new process is simple and clean.
- Chen, Xinzhi,Zhou, Shaodong,Qian, Chao
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experimental part
p. 179 - 185
(2012/05/21)
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- Solvent-free synthesis of thiophenol using uncatalyzed transfer hydrogenation
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Clean and sustainable transfer hydrogenation for aryl sulfonamides and sulfonyl chlorides is described. The protocol is chemoselective and uses neither catalyst nor solvent.
- Zhou, Shaodong,Qian, Chao,Chen, Xinzhi
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experimental part
p. 2432 - 2439
(2012/06/18)
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- Kinetics and mechanism of the aminolysis of O-methyl S-aryl thiocarbonates in acetonitrile
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The aminolysis of O-methyl S-aryl thiocarbonates with benzylamines are studied in acetonitrile at -45.0°C. The βX (βnuc) values are in the range 0.62-0.80 with a negative cross-interaction constant, ρXZ = -0.42, which are interpreted to indicate a concerted mechanism. The kinetic isotope effects involving deuterated benzylamine nucleophiles (XC6H 4CH2ND2) are large, kH/kD = 1.29-1.75, suggesting that the N-H(D) bond is partially broken in the transition state by forming a hydrogen-bonded four-center cyclic structure. The concerted mechanism is enforced by the strong push provided by the MeO group which enhances the nucleofugalities of both benzylamine and arenethiolate from the putative zwitterionic tetrahedral intermediate.
- Oh, Hyuck Keun
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scheme or table
p. 1539 - 1542
(2011/12/04)
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- Kinetics and mechanism of the aminolysis of aryl N-benzyl thiocarbamates in acetonitrile
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The aminolysis reactions of phenyl N-benzyl thiocarbamate with benzylamines in acetonitrile at 50.0 °C are investigated. The reactions are first order in both the amine and the substrate. Under amine excess, pseudo-first coefficient (kobs) are obtained, plot of kobs vs free amine concentration are linear. The signs of ρXZ (X and ρZ with respect to the sustituent in the substrate and large ρXZ value indicate that the reactions proceed concerted mechanism. The normal kinetic isotope effects (kH/k D = 1.3 ～ 1.5) involving deuterated benzylamine nucleophiles suggest a hydrogen-bonded, four-centered-type transition state. The activation parameters, ΔH?and AS?, are consistent with this transition state structure.
- Oh, Hyuck Keun
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experimental part
p. 137 - 140
(2011/11/01)
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- Novel cruciform structures as model compounds for coordination induced single molecule switches
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We have synthesized various molecular cruciforms consisting of two different crossing π-systems and comprising crosswise arranged thiol- and pyridine-anchor groups. With these model compounds we strive towards the investigation of a new switching concept based on the potential dependent coordination of pyridines to gold electrodes in an electrochemical set-up. Integration of these cruciform molecules between both electrodes of a mechanically controlled break junction in a liquid environment gave insight into their single molecule transport properties. These studies allowed individual transport characteristics to be assigned to the bar subunits of the cruciforms but also revealed the remaining experimental challenges to realize the suggested switching concept. Schweizerische Chemische Gesellschaft.
- Grunder, Sergio,Huber, Roman,Wu, Songmei,Schoenenberger, Christian,Calame, Michel,Mayor, Marcel
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p. 140 - 144
(2011/08/04)
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- Copper-catalyzed coupling of thiourea with aryl iodides: The direct synthesis of aryl thiols
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A general, economical and efficient protocol for the direct copper-catalyzed coupling of thiourea with aryl iodides is developed and it will be potentially applied in large-scale industry as a preferred process.
- Qiao, Shu,Xie, Kun,Qi, Junsheng
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scheme or table
p. 1441 - 1443
(2011/01/04)
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- A general and efficient approach to aryl thiols: Cul-catalyzed coupling of aryl iodides with sulfur and subsequent reduction
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A Cul-catalyzed coupling reaction of aryl iodides and sulfur powder takes place in the presence of K2CO3 at 90 °C. The coupling mixture is directly treated with NaBH4 or triphenylphosphine to afford aryl thiols in good to
- Jiang, Yongwen,Qin, Yuxia,Xie, Siwei,Zhang, Xiaojing,Dong, Jinhua,Ma, Dawei
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supporting information; scheme or table
p. 5250 - 5253
(2009/12/28)
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- A simple, fast and chemoselective method for the preparation of arylthiols
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An efficient and convenient method for the synthesis of arylthiols by reaction of sulfonyl chlorides with triphenylphosphine in toluene is reported.
- Bellale, Eknath V.,Chaudhari, Mahesh K.,Akamanchi, Krishnacharya G.
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experimental part
p. 3211 - 3213
(2010/03/01)
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- Flow-vacuum pyrolysis of polycyclic compounds. 251. Pyrolysis of some 3-mercapto-5-substituted-1,2,4-triazoles
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The flow-vacuum pyrolysis (FVP) of the 3-mercapto-5-substituted-1,2,4- triazoles 5a-c, between 475°C - 750°C, at 2 mm Hg, in inert atmosphere (4mL/min argon flow rate) and quartz pyrolysis tube (60 cm length, 1 cm internal diameter, quartz chips filling 30 mm long) afforded a complex mixture with cyano-diphenyl-sulphones 12a-c and corresponding diphenylsulphones 13a-c as main products. The reaction products were identified by GC/MS. A radical mechanism is suggested in order to explain the formation of the main reaction products.
- Istrati, Daniela,Popescu, Angela,Mihaiescu, Dan,Saramet, Ioana,Bala?u, Mihaela C.
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experimental part
p. 497 - 503
(2009/05/11)
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- PROCESS FOR PREPARATION OF THIOPHENOL DERIVATIVES
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Provided is a process for preparing thiophenol derivatives, using aromatic disulfide as a starting material, and inexpensive sodium bisulfite (NaHSO3) as a reducing agent. The process can be carried out on an industrial scale at low production costs, secures advantageous reaction conditions by using a small amount of water- soluble alcohol solvent. Further, the process can maximize the purity of the products by inhibiting reverse oxidation of the final product by the action of sulfur dioxide (SO2) produced during the preparation process, after solvent extraction of the starting materials present as impurities of the thiophenol derivatives.
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Page/Page column 9-10
(2008/06/13)
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- Kinetics and mechanism of the aminolysis of S-aryl O-ethyl dithiocarbonates in acetonitrile
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The aminolysis of S-aryl O-ethyl dithiocarbonates with benzylamines are studied in acetonitrile at -25.0°C. The βX (βnuc) values are in the range 0.67-0.77 with a negative cross-interaction constant, ρXZ = -0.24, which are interpreted to indicate a concerted mechanism. The kinetic isotope effects involving deuterated benzylamine nucleophiles (XC6H4CH 2ND2) are large, kH/kD = 1.41-1.97, suggesting that the N-H(D) bond is partially broken in the transition state by forming a hydrogen-bonded four-center cyclic structure. The concerted mechanism is enforced by the strong push provided by the EtO group which enhances the nucleofugalities of both benzylamine and arenethiolate from the putative zwitterionic tetrahedral intermediate.
- Oh, Hyuk Keun,Oh, Ji Young,Sung, Dae Dong,Lee, Ikchoon
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p. 2174 - 2182
(2007/10/03)
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- Nucleophilic Substitution Reactions of Aryl N-Phenyl Thiocarbamates with Benzylamines in Acetonitrile
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The aminolysis reactions of aryl N-phenythiocarbamates (PhNHC(=O)SC 6H4Z; 3b) with benzylamines (XC6H 4CH2NH2) acetonitrile are studied. Rates are much faster than the corresponding reactions of aryl N-phenylcarbamates (PhNHC(=O)OC6H4Z; 3a). The rate increase from 3a to 3b is greater than that expected from substitution of thiophenoxide for phenoxide leaving group in the stepwise aminolysis reactions of esters. This large rate increase and the similar change in the aminolysis rates that are reported to occur from aryl ethyl carbonate (EtOC(=O)OC6H4Z; 2a) to aryl ethylthiocarbonate (EtOC(=O)SC6H4Z; 2b) lead us to conclude that the aminolysis of 3b proceeds by a concerted mechanism in contrast to a stepwise process for 3a. The negative ρxz values (-0.63) and violation of the reactivity-selectivity principle (RSP) support the proposed mechanism. The large βx values (1.3-1.5) obtained are considered to indicate a large degree of bond making in the transition state, which is consistent with the relatively large kinetic isotope effects (k H/kD > 1.0) observed.
- Oh, Hyuck Keun,Park, Jie Eun,Sung, Dae Dong,Lee, Ikchoon
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p. 3150 - 3153
(2007/10/03)
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- Kinetics and mechanism of the aminolysis of aryl propanedithioates in acetonitrile
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The kinetics and mechanism of the aminolysis of aryl proanedithioates with benzylamines are investigated in acetonitrile at - 35.0 °C. A large magnitude of the Hammett (ρx and ρz) and Broensted (βx and βz) coefficients and exceptionally large cross-interaction constant ρxz(= 3.5) are consistent with a stepwise mechanism in which leaving group expulsion from an intermediate, T±, is the rate-determining step. The faster rates observed for dithio esters (I1) than for thio esters (I), and the validity of the reactivity-selectivity principle (RSP) are also in line with the mechanism proposed. The kH/kD values (= 1.0-1.8) determined with deuterated benzylamines (XC6H4CH2ND2) and the activation parameters, ΔH≠(?8 kcal mol-1) and ΔS≠(= -16 to -23 e.u.), suggest that proton transfer occurs concurrently with leaving group departure in the transition state.
- Hyuck Keun Oh,Sun Kyung Kim,Hai Whang Lee,Lee
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p. 313 - 317
(2007/10/03)
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- Oxidative Cleavage of S-Arylmercaptoacetic Acids by Sodium Perborate: Kinetic and Correlation Study
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Kinetics of oxidation of twenty six S-arylmercaptoacetic acids (SAMA) (I) by sodium perborate (PB) have been studied in acid medium.The product of oxidation is the corresponding thiophenol.The rate data of meta- and para-substituted acids have been correlated with DSP equations.While the para-compounds correlate well with ?I and ?0R values, the meta-compounds correlate well with ?I and ?-R values.The reaction constants are negative and of smaller magnitudes.Further, the ortho-substituted acids show a good correlation with a triparametric equation involving Taft's ?I and ?0R and Charton's steric parameter ν.There is a considerable steric contribution to the total ortho-substituent effect.Based on these observations, mechanism involving the formation of protonated arylsulfinylacetic acid intermediate, followed by an intramolecular rearrangement leading to the product thiophenol has been proposed.
- Kabilan, S.,Pandiarajan, K.,Krishnasamy, K.,Sankar, P.
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p. 443 - 452
(2007/10/02)
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- Kinetic Studies of the Reactions of Some Phenyl Aryl Sulfides with Aliphatic Amines in Dimethyl Sulfoxide: the Mechanism of Base Catalysis
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The reaction of n-butylamine, pyrrolidine and piperidine with 4'-R-phenyl 2,4,6-trinitrophenyl sulfides (R = H, Me, Br, NO2), 4a-d, result in the rapid formation of ?-adducts by attack at the unsubstituted 3-position; rate and equilibrium data are reported and substituent effects examined. Attack by amine at the 1-position of of 4a-d, phenyl 2,4-dinitronaphthyl sulfide 9, and phenyl 2,6-dinitro-4-trifluoromethyl sulfide 11, results in displacement of the phenylthio group.The substitutions by butylamine show a first order dependence on the amine concentration indicating that nucleophilic attack is rate determining.However the substitutions by pyrrolidine are subject to general base catalysis and it is argued that here the rate limiting step is deprotonation of the initially formed zwitterionic intermediate.
- Chamberlin, Rachel A.,Crampton, Michael R.
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p. 425 - 432
(2007/10/02)
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- Kinetic and Equilibrium Studies of ?-Adduct Formation and Nucleophilic Substitution in the Reactions of Hydroxide Ions with 2,4,6-Trinitrophenyl Sulfides and Ethers
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Kinetic and equlibrium data are reported for reaction of hydroxide ions in 20/80 DMSO/water (v/v) with a series of 4'-substituted phenyl 2,4,6-trinitrophenyl sulfides, 1, and with ethyl thiopicrate, 2, ethyl picrate, 3, phenyl picrate, 4, and 1,3,5-trinitrobenzene, 5.In each case a rapid reaction is observed involving reversible hydroxide addition at an unsubstituted ring-position.In the case of 1-4 this is followed by slower, irreversible attack at the 1-position leading to the formation of picric acid.The Hammett ρ value for equilibrium addition of hydroxide to the 3-position of 1 is 0.98, and the ρ value for rate constants for attack at the 1-position is 0.62.The results are discussed in terms of the electronic and steric effects of the 1-substituents.Comparison of 1-5 indicates that changing from an OR to SR group introduces additional steric crowding.However for the reactions studied changing from R = Et to R = Ph has little steric consequence.
- Chamberlin, Rachel,Crampton, Michael R.,Knight, Roland L.
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p. 2986 - 2998
(2007/10/02)
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- Ether derivative and an acaricidal or insecticidal composition comprising said derivative
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An ether derivative compound of the formula: STR1 wherein R1 is hydrogen, chloro, methyl or (C1 -C3)-alkoxy, R2 is (C1 -C6)-alkyl, R3 is hydrogen, chloro, bromo, fluoro, --CF3, nitro, (C1 -C4)-alkyl, methoxy, phenoxy or (C1 -C3)-alkylthio, R4 is hydrogen, chloro or methyl, Y is oxygen, sulfur, sulfinyl, sulfonyl, or imino, x is 0, 1 or 2, y is 0 or 1, a is 0 or 1, b is an integer of 0 to 6, c is 0 or 1, d is 0, 1 or 2, e is 0 or 1, except that all of a, b and c are zero.
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- THE JOINT EFFECT OF THE STRUCTURE, MEDIUM, AND TEMPERATURE FACTORS ON THE ALKALINE HYDROLYSIS OF S- ARYL THIOACETATES IN WATER-ETHANOL MIXTURES. COMPARISON WITH THE OXYGEN ANALOGS
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The joint effect of the structure (the substituent X), the composition of the water-ethanol medium, and the temperature on the bimolecular alkaline cleavage of esters AcSC6H4X was studied by spectrophotometry.Limited observance of the LFE principle was demonstrated for the medium.In the region of high ethanol contents (50-90 vol. percent) a polylinear equation describing the effect of all the factors was obtained, and nonadditivity was found in the effects of the structure and the medium.Similarity was found in the relationships govering the effects of the three factors on hydrolysis of the esters and their oxygen analogs.It is suggested that the thio esters, like aryl acetates, are hydrolyzed by an addition-elimination mechanism (BAc2).
- Bazhenov, B. N.,Baranskii, V. A.,Aliev, I. A.
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p. 2146 - 2151
(2007/10/02)
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- RELATIONSHIPS IN THE ALKALINE HYDROLYSIS OF S-ARYL THIOACETATES IN MIXTURES OF WATER WITH DIOXANE AND ACETONITRILE
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The joint effect of the structure (the substituent X) and composition factors in water-dioxane and water-acetonitrile mixtures on the kinetics of the alkaline hydrolysis of esters AcSC6H4X was studied by spectrophotometry at 25 deg C.The obtained relationships were compared with those obtained earlier for the esters AcOC6H4X.It was found that with increase in the content of the organic component in the binary solvent there is a sharp change in the nature of the joint effect of the factors on the hydrolysis of both types of ester.It was suggested that this change is not due to change in the mechanism of the processes but results only from solvation effects.
- Bazhenov, B. N.,Zasukhina, E. Yu.,Baranskii, V. A.,Aliev, I. A.
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p. 2152 - 2156
(2007/10/02)
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- SYNTHESIS OF AROMATIC THIOLS FROM ARYL IODIDES AND THIOUREA BY MEANS OF NICKEL CATALYST
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Nickel(0) complex, generated in situ from bis(triethylphosphine)nickel(II) chloride and sodium cyanoborohydride, catalyzed the nucleophilic displacement of aryl iodides with thiourea.S-Aryl-isothiuronium salts or aromatic thiols were obtained in good yields after simple work-up procedures.
- Takagi, Kentaro
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p. 1307 - 1308
(2007/10/02)
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- SYNTHESIS AND CONFIGURATIONAL STUDIES OF ARYL CYCLOPROPYL SULFONES
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The cycloaddition of arylthiocarbenes to styrene gave stereospecifically cis-1-(arylthio)-2-phenylcyclopropanes, which were subsequently oxidized to the corresponding sulfones.The cyclopropanation of α,β-unsaturated sulfones with dimethylsulfonium methylide yielded stereoselectively trans-1-(arylsulfonyl)-2-arylcyclopropanes.The configurational assignments of these compounds have been arrived at on the basis of IR and PMR spectral data.Chemical shifts for ring protons and other substituents reveal that all the substituents tend to cause protons cis to them to appear at higher fields than those trans to them.This has been used as a criterion to distinguish between cis and trans aryl cyclopropyl sulfones.
- Reddy, D. Bhaskar,Balaji, T.,Reddy, B. Venkataramana
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p. 297 - 306
(2007/10/02)
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- A NEW SYNTHESIS OF AROMATIC THIOLS
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Benzenoid and heterocyclic lithio derivatives react smoothly with tetraisopropylthiuram disulfide to give highly crystalline and readily purified S-aryl-N,N-diisopropyldithiocarbamates, which yield aromatic thiols on alkaline hydrolysis.
- Jen, Kwan-Yue,Cava, Michael P.
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p. 2001 - 2004
(2007/10/02)
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- Electrophilic Aromatic Substitution. Part 33. Partial Rate Factors for Protiodetritiation of Benzothiophen; the Resonance-dependent Reactivity of the Ring Positions
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Rate coefficients for detriation of benzothiophen, specifically labelled with tritium at each position, have been measured in anhydrous trifluoroacetic acid, and, for benzothiophen, in a range of trifluoroacetic acid-acetic acid mixtures, all at 70 deg C.The dependence of rate upon acidity is consistent with the effect of hydrogen bonding between sulphur and trifluoroacetic acid, as found previously for other sulphur-containing heterocycles.Partial rate factors, corrected for the effect of hydrogen bonding are (positions in parentheses): 8.84 * 105 (2); 1.18 * 106 (3); 360 (4); 13200 (5); 16200 (6); and 26.2 (7); the corresponding ?+ values are -0.68, -0.695, -0.29, -0.47, -0.48, and -0.16.The positional reactivity order is the same as found in pyrolysis of 1-arylethyl acetates, and solvolysis of 1-arylethyl chlorides, but the ?+ values are more negative due to the greater demand for resonance stabilization of the transition states in hydrogen exchange.Comparison of the 2- : 3-isomer ratios in various substitutions leads to the unexpected conclusion that substitution at the 2-position is subject to steric effects, probably due to the proximity of the sulphur d-orbitals.
- Amin, Hassan B.,Awad, Amin A.,Archer, William J.,Taylor, Roger
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p. 1489 - 1492
(2007/10/02)
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- Electrophilic additions to allenes. VI. The role of steric versus electronic effects in the reactions of arenesulphenyl halides with allenes
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The role of steric and electronic effects during the rate and product determining steps for the addition of arenesulphenyl chlorides to 1,3-disubstituted allenes has been briefly examined.Both effects appear to be generally of minimal importance during the rate determinig step.The available rate data indicate the presence of little, if any, build up of positive charge on sulphur.These results are interpreted in terms of an SN2 attack on bivalent sulphur leading to an alkylidenethiiranium ion intermediate.Steric effects are of greater importance in the product determinig step, particularly when the sulphenyl chlorides possess two bulky ortho substituents, as in the case of 2,4,6-triisopropylbenzenesulphenyl chloride.
- Garratt, Dennis G.,Beaulieu, Pierre L.
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p. 2738 - 2744
(2007/10/02)
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- Cephalosporin displacement reaction
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The present invention is directed to a process for the displacement of the acetoxy group of a cephalosporanic acid by a sulfur nucleophile, in an organic solvent and under essentially anhydrous conditions.
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- Pesticidal compositions containing phosphoric esters and divalent sulphur compounds
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Pesticidal composition comprising: a pesticidal, phosphoric ester the molecule of which has at least one alkyl group of 1 to 3 carbon atoms, 0.05 to 10% of an agent stabilizing the said ester against decomposition by protonisation, together with adjuvants characterized in that the stabilizing agent comprises at least one sulphur compound containing per molecule at least one divalent sulphur atom of which one valence is bonded to an atom chosen from sulphur, carbon, nitrogen, hydrogen, and metals capable of giving a salt, the other valence being bonded to an atom chosen from hydrogen, the carbon atom already noted, a second carbon atom, the nitrogen atom already noted, a second nitrogen atom, the metal atom already noted in the case of a metal of valence greater than one, a second atom of metal and oxygen when the first valence is not attached to an atom of hydrogen, the proportion of sulphur calculated with reference to the weight of the sulphur compound being between 5 and 99%. Process for stabilizing a phosphoric ester of which the molecule possesses at least one alkyl group containing 1 to 3 carbon atoms characterized in that there is added to the phosphoric ester or to a mixture which contains it, 0.05 to 10% calculated on the weight of the phosphoric acid ester of an agent capable of stabilizing the said phosphoric ester against protonisation and comprising at least one sulphur compound such as that defined thereupon.
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