- The mechanisms of acid-catalyzed hydrolysis of n-(4-substituted arylthio) phthalimides
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The acid-catalyzed hydrolysis of N-(4-substitutedarylthio)phthalimides was studied in aqueous solutions of sulfuric, perchloric, and hydrochloric acids at 40.0 ±0.1° C. Analysis of the data by the excess acidity method, activation parameters, and substituent effects indicates hydrolysis by an A-2 mechanism at low acidity. At higher acidities, a changeover to an A-1 mechanism is observed.
- Kutuk, Halil,Yakan, Hasan
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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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- Evidence for complexes of different stoichiometries between organic solvents and cyclodextrins
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The influence of the organic solvent on the acid and basic hydrolysis of N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) in the presence of α- and β-cyclodextrins has been studied. The observed rate constant was found to decrease through the formation of an unreactive complex between MNTS and the cyclodextrins. In the presence of dioxane, acetonitrile or DMSO, the inhibitory effect of β-CD decreased on increasing the proportion of organic cosolvent as a result of a competitive reaction involving the formation of an inclusion complex between β-CD and the cosolvent. The disparate size of the organic solvent molecules resulted in stoichiometric differences between the complexes; the β-CD-dioxane and β-CD-DMSO complexes were 1: 1 whereas the β-CD-acetonitrile complex was 1: 2. The basic and acid hydrolysis of MNTS in the presence of α-CD showed a different behavior; thus, the reaction gave both 1: 1 and 2: 1 α-CD-MNTS complexes, of which only the former was reactive. This result was due to the smaller cavity size of α-CD and the consequent decreased penetration of MNTS into the cavity in comparison to β-CD. The acid hydrolysis of MNTS in the presence of α-CD also revealed decreased penetration of MNTS into the cyclodextrin cavity, as evidenced by the bound substrate undergoing acid hydrolysis. In addition, the acid hydrolysis of MNTS in the presence of acetonitrile containing α-CD gave 1: 1 α-CD-acetonitrile inclusion complexes, which is consistent with a both a reduced cavity size and previously reported data. The Royal Society of Chemistry 2006.
- Garcia-Rio,Herves,Leis,Mejuto,Perez-Juste,Rodriguez-Dafonte
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- Removal of electrophilic potential genotoxic impurities using nucleophilic reactive resins
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Potential genotoxic impurities (PGI) are chemical compounds that could potentially damage DNA and lead to mutation. Controlling the occurrence of PGIs in active pharmaceutical ingredients (APIs) poses a big challenge for chemists, as levels of these compounds must be reduced well below the amounts required for other types of less toxic impurities. In situations where formation of PGIs cannot be avoided, an ideal solution would allow the complete removal of PGIs after the synthesis is complete, for example, by recrystallization, preparative chromatography or other downstream processing approaches. Some disadvantages of using these approaches are potential high yield loss, high solvent consumption, and additional time and resources required for process development. In this work, we present a simple and rapid approach to remove electrophilic PGIs from APIs. A selected nucleophilic resin can be added to the final API solution to reduce or totally remove the PGI. Esters of methanesulfonic acid (MSA), benzenesulfonic acid (BSA), and ρ-toluenesulfonic acid (pTSA) were used as model electrophilic PGIs. Several nucleophilic resins were screened, and the resins with the highest efficiency of PGI removal were chosen. A recommended procedure is presented for the removal of MSA, BSA, and pTSA esters. The kinetics of PGI removal, resin loading capacity, solvent effects, and API matrix effects are demonstrated.
- Lee, Claire,Helmy, Roy,Strulson, Christopher,Plewa, Jolanta,Kolodziej, Elizabeth,Antonucci, Vincent,Mao, Bing,Welch, Christopher J.,Ge, Zhihong,Al-Sayah, Mohammad A.
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- ESR study of free radical decomposition of N,N-bis(arylsulfonyl)hydroxylamines in organic solution
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Decomposition of N,N-bis(p-tolylsulfonyl)hydroxylamine (BTH) in chloroform and benzene solutions has been studied and was found to involve the formation of several radical intermediates. This process has been found to be accelerated by oxygen, resulting in the formation of p-toluenesulfonic acid and N,N,O-tris(p-tolylsulfonyl)hydroxylamine (TTH) as the main decay products. In addition, a small amount of p-toluenesulfonyl chloride has been isolated from chloroform solution, suggesting the chlorine abstraction from solvent. The formation of nitric oxide (NO) from BTH has been shown by mass spectrometry in gaseous phase and using nitronyl nitroxide as an NO trap in solution. It was proposed that liberation of NO proceeds through the homolytic cleavage of the S-N bond of p-tolylsulfonyl nitrite existing in equilibrium with BTH in solution. The formation of p-tolylsulfonyl radicals has been proved by spin trapping using 2-methyl-2-nitrosopropane (MNP) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The rate of NO production in the presence of nitronyl nitroxide and the rate of oxygen consumption revealed linear plots in BTH concentration with the rate constants 0.0044 s-1 and 0.0016 s-1, respectively. It was found also that nitrogen dioxide formed during NO oxidation reacts readily with BTH to produce the organic analog of Fremy's radical. This radical recombines with p-tolylsulfonyl radical yielding N,N,O-trisubstituted hydroxylamine TTH.
- Balakirev, Maxim Yu.,Khramtsov, Valery V.
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- Investigation of micellar media containing ?2-cyclodextrins by means of reaction kinetics: Basic hydrolysis of N-methyl-N-nitroso-p-toluenesulfonamide
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The kinetics of the basic hydrolysis of N-methyl-N-nitroso-p-toluenesulfonamide were studied in media containing sodium dodecyl sulfate (SDS) or tetradecyltrimethylammonium bromide (TTABr) micelles and ?2-cyclodextrin (CD). Under the experimental conditions, [NaOH] = 0.17 M, all CD will have been deprotonated; thus, binding constants apply to the CD anion. The results have been interpreted in terms of a pseudophase model that takes into account the formation of both CD - surfactant and CD - substrate complexes and also, for TTABr systems, the exchange of Br- and OH- ions between the micellar and aqueous pseudophases. The presence of CD has no effect on existing SDS or TTABr micelles but raises the cmc: complexation of surfactant by cyclodextrin makes the cmc dependent on CD concentration because the cmc is now the sum of the concentrations of free and complexed surfactant when micelles begin to form; increasing [CD] reduces the former quantity but increases the latter to a greater extent. At surfactant concentrations above the cmc, competition between the micellization and complexation processes leads to the existence of a significant concentration of free cyclodextrin.
- Garciì?a-Riì?o,Leis,Mejuto,Peì?rez-Juste
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- Hydrogenolysis of 2-tosyloxy-1,3-propanediol into 1,3-propanediol over Raney Ni catalyst
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2-Tosyloxy-1,3-propanediol (TPD), a potential precursor for 1,3-propanediol (1,3-PD) production, is produced by the tosylation of glycerol with the help of protecting group techniques. In this work, the hydrogenolysis of TPD into 1,3-PD over Raney Ni catalyst is discussed at different reaction parameters to optimize the reaction conditions for selective formation of 1,3-PD. The mechanisms of the hydrogenolysis of TPD and the side reactions were also confirmed by gas chromatography-mass spectrometry (GC-MS) technique.
- Zheng, Zhi,Wang, Jianli,Lu, Zhen,Luo, Min,Zhang, Miao,Xu, Lixin,Ji, Jianbing
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- The quest for sulfoquinone imine intermediates in the reaction of sulfanilic acid derivatives with nucleophiles
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Data from kinetic and trapping studies suggest that the alkaline hydrolyses of sulfanilyl chloride and of the corresponding N-acetyl derivative follow different reaction pathways. While results for the latter compound are fully consistent with the occurrence of the common associative, SN2 mechanism, the former shows somewhat different features suggesting the incursion of a mechanism of the dissociative type involving a sulfoquinone imine species as a reaction intermediate. The alkaline hydrolyses of the corresponding sulfonyl fluorides and 2,4-dinitrophenyl esters, whose leaving groups are worse than Cl- as leaving groups, are all associative.
- Thea, Sergio,Vigo, Daniele,Cevasco, Giorgio
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- Influence of colloid suspensions of humic acids on the alkaline hydrolysis of N-methyl-N-nitroso-p-toluene sulfonamide
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The influence of humic substances (HSs) upon the alkaline hydrolysis of N-methyl-N-nitroso-p-toluene sulfonamide has been studied. Important inhibition of hydrolysis reaction has been reported. This inhibition has been explained in terms of association of reactants to the humic substances. Kinetic results have been modeled using the micellar pseudophase model.
- Astray,Garcia-Rio,Lodeiro,Mejuto,Moldes,Morales,Moyano
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- General, fast, and high yield oxidation of thiols and disulfides to sulfonic and sulfinic acids using HOF·CH3CN
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Thiols and disulfides are oxidized to the corresponding sulfonic and sulfinic acids using HOF·CH3CN. This oxidation is suitable for a variety of thiols and disulfides and proceeds under mild conditions, in short reaction times and with high yields.
- Shefer, Neta,Carmeli, Mira,Rozen, Shlomo
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- Hypervalent iodine in synthesis. XXI: A facile method for the preparation of thiosulfonic S-esters by the oxidation of diaryl disulfides or thiophenols with phenyliodine(III) bis(trifluoroacetate)
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Phenyliodine(III) bis(trifluoroacetate) can be used to readily oxidize diaryl disulfides or thiophenols to corresponding thiosulfonic S-esters with good yields under very mild conditions.
- Xia, Min,Chen, Zhen-Chu
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- Competitive electron transfers from a tyrosyl side-chain and peptide bond in the photodegradation of N-tosyl α-aminomethylamides: An insight into photosynthesis and photodamage in the biological oxidation of water?
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Photo-excited N-tosyl derivatives of phenylalanyl- and, more particularly, O-methyltyrosylmethylamides undergo electron transfer from aryl to tosyl groups whereas the photo-degradation of aliphatic analogues is initiated by electron transfer from the peptide bond, suggesting the latter as one possible reason for the rapid turnover of the D1 protein in biological water oxidation when the essential mediating role of tyrosine 116 in the PSII complex is inhibited.
- Hill, Roger R.,Moore, Sharon A.,Roberts, David R.
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- Formation of o-nitrosobenzaldehyde from hydrolysis of o-nitrobenzyl tosylate. Evidence of intramolecular nucleophilic interaction
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Hydrolysis of o-nitrobenzyl tosylate in CH3CN:H2O (1:1, v/v) gave o- nitrobenzyl alcohol and o-nitrosobenzaldehyde in 1.8 : 1 ratio. Formation of o-nitrosobenzaldehyde indicates that the nitro group participates in the leaving of the tosylate group. o-Nitrosobenzaldehyde was reduced by biological thiols to give o-aminobenzaldehyde. Reaction of o- nitrosobenzaldehyde with 1 tool of benzylamine afforded 3-(N- benzylamino)anthranil (or its tautomer) as a major product.
- Chen, Ling-Jen,Burka, Leo T.
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- Palladium nanoparticles as reusable catalyst for the synthesis of N-aryl sulfonamides under mild reaction conditions
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An efficient palladium nanoparticles-catalyzed N-arylation of sulfonamides and sulfonyl azides is described. This procedure serves as an active protocol for intermolecular C-N bond formation using Pd(OAc)2 in PEG-400 under air. Aryl bromides and triflates react at 35°C, while aryl chlorides require heating to 50°C and give the desired products only in low yields. This reaction proceeds smoothly in acceptable yields using low catalyst loading.
- Khalaj, Mehdi,Ghazanfarpour-Darjani, Majid,Talei Bavil Olyai, Mohamad Reza,Shamami, Sakineh Faraji
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- Experimental and molecular modelling studies on aromatic sulfonation
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The mechanism of the sulfonation of toluene has been explored both experimentally and theoretically using molecular orbital methods. Sulfonation with sulfur trioxide is proposed to proceed initially via the formation of a toluene-S2O6 π-complex (3) which rearranges to form a Wheland pyrosulfonate intermediate (5) which in turn undergoes a facile prototropic rearrangement involving the transfer of the ring hydrogen at the sp3 carbon to the sulfonate oxygen atom to form toluenepyrosulfonic acid (7). Once formed, this acid is thought to attack toluene to form two equivalents of toluenesulfonic acid (6) which preferentially react with sulfur trioxide to re-form the pyrosulfonic acid (7). Experimentally, sulfonation using either acetylsulfonic acid (9), trifluoroacetylsulfonic acid (10), or trimethylacetylsulfonic acid (11), as models for pyrosulfonic acid (7), appears to show second order kinetics at room temperature. The reaction with acetylsulfonic acid (9) shows no significant kinetic isotope effect when 4deuterotoluene is used as the substrate, suggesting that sulfonation proceeds via attack of the π-electrons of the toluene ring at the sulfur atom, S8, of acetylsulfonic acid or toluenepyrosulfonic acid with simultaneous cleavage of the O7-S8 bond, where the displaced acetate or toluenesulfonate anion respectively can facilitate the removal of the ring proton at the sp3 carbon.
- Morley, John O.,Roberts, David W.,Watson, Simon P.
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- Photodegradation of aryl sulfonamides: N-tosylglycine
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Continuing uncertainty about pathways and consequences of the photolability of aryl sulfonamides is partly resolved by the results of comprehensive product analysis in the photolysis of aqueous N-tosylglycine, which indicate that intramolecular electron or hydrogen transfer (according to conditions) promote the widely reported S-N cleavage and reveal the nature of subsequent and competing processes.
- Hill, Roger R.,Jeffs, Graham E.,Roberts, David R.,Wood, Sharon A.
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- A novel method for sulfonation of aromatic rings with silica sulfuric acid
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Direct and chemoselective sulfonation of aromatic compounds with silica sulfuric acid in 1,2-dichloeoethane or under solvent-free conditions.
- Hajipour, Abdol R.,Mirjalili, Bi Bi F.,Zarei, Amin,Khazdooz, Leila,Ruoho
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- Regioselective Sulfonation of Aromatic Compounds over 1,3-Disulfonic Acid Imidazolium Chloride under Aqueous Media
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1,3-Disulfonic acid imidazolium chloride ([Dsim]Cl), as a Bronsted acidic ionic liquid, is introduced for the sulfonation of aromatic compounds by in situ generation of sulfuric acid at 50 °C under mild conditions and in aqueous medium.
- Moosavi-Zare, Ahmad Reza,Zolfigol, Mohammad Ali,Noroozizadeh, Ehsan
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- Reactions of the Nickel(I) Octaethylisobacteriochlorin Anion with Alkyl Halides
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Reactions of NiI(OEiBC)- with alkyl halides were investigated in bulk solution and by electrochemical means.With the exception of factor F430, the Ni hydrocorphinoid prosthetic group of methyl coenzyme M reductase, Ni(OEiBC) is the only tetrapyrrole to date that has been reduced to an isolable nickel(I) complex.NiI(OEiBC)- reacts with CH3I in a 2:1 stoichiometry to afford neutral NiII(OEiBC) in quantitative yield and CH4 and I- in lesser yields.The nickel(I) complex also reacts with methyl p-toluenesulfonate to afford CH4.Ni(OEiBC) mediates electrocatalytic reductions of alkyl halides and of methyl p-toluenesulfonate.Evidence is presented for a transient alkyl-NiIII(OEiBC) intermediate, which is reducible at potentials positive of the NiII/NiI couple.The current/potential curves of the electrocatalytic reductions were analyzed to obtain relative rate constants for a series of alkyl halides.The reactivity trends I > Br > tosyl >/= Cl and CH3 > n-C4H9 > sec-C4H9 > t-C4H9 are consistent with a nucleophilic, Sn2-like mechanism.Estimates of the second-order rate constant for reaction of NiI(OEiBC)- and CH3I suggest that the nucleophilicity of the nickel(I) complex is comparable to that of the "supernucleophile" vitamin B12s.
- Stolzenberg, Alan M.,Stershic, Matthew T.
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- A Novel Concept of Acid Proliferation. Autocatalytic Fragmentation of an Acetoacetate Derivative as an Acid Amplifier
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tert-Butyl 2-methyl-2-(p-toluenesulfonyloxymethyl)acetoacetate was designed to be subjected to the acid-catalyzed fragmentation to liberate p-toluenesulfonic acid which can act as the autocatalyst to lead to the increment of the acid concentration in geometric progression.
- Ichimura, Kunihiro,Arimitsu, Koji,Kudo, Kazuaki
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- Suzuki Cross-Coupling for the incorporation of labeled methyl groups onto aryl halides. A synthesis of [14C]Tosyl chloride and its use in the synthesis of [14C]L-738,167
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A synthesis of [4-methyl-14C]tosyl chloride has been developed which utilizes a Suzuki Cross-Coupling reaction between 4-iodophenylsulfonic acid and a labeled methyl borinate as the key step. This process avoids the poor regioselectivity typically attendant with aromatic sulfonation procedures. We now describe the use of this [14C]tosyl chloride in the synthesis of the orally active fibrinogen receptor antagonist L-738,167.
- Braun, Matthew P.,Dean, Dennis C.,Melillo, David G.
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- Potential photoacid generators based on oxime sulfonates
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The bis-oxime of acenaphthenequinone and the mono-oxime of benzil have been sulfonated by reaction with 4-methylbenzenesulfonyl chloride and propylsulfonyl chloride. The four sulfonated oximes were characterised by X-ray single-crystal structure determinations. Some photochemical decompositions were studied using a 6-W 254-nm immersion well lamp in dichloromethane. The 4-methylbenzenesulfonate bis-oxime of acenaphthenequinone and the 4-methylbenzenesulfonate mono-oxime of benzil both give 4-methylbenzenesulfonic acid upon irradiation but not 4-methylbenzenesulfinic acid. Fragmentation pathways are discussed. The possible use of these compounds as photoacid generators in polymer resists and the role of secondary reactions to liberate acid is discussed.
- Plater, M. John,Harrison, William T. A.,Killah, Ross
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- Importance of repulsion of lone electron pairs in the enhanced reactivity of 1,8-naphthyridine and the large α-effect of hydrazine in the aminolyses of p-toluenesulfonyl chloride
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The rates of aminolyses of p-toluenesulfonyl chloride with primary and tertiary amines have been determined both in acetonitrile and in ethanol.The Broensted plots of log krel again pKa' values fo amines (except hydrazine and 1,8-naphthyridine in acetonitrile) gave a good correlation when the aminolyses were carried out in acetonitrile.In ethanol, however, although Broensted plots with all tertiary amines show a good correlation, less basic hydrazine shows a higher reactivity than n-butylamine.The abnormal rate enhancement found with hydrazine is undoubtedly due to the α-effect, while with 1,8-naphthyridine in acetonitrile is considered to be due to the repulsion of two lone electron pairs on the two nitrogen atoms in 1,8-naphthyridine.
- Oae, Shigeru,Kadoma, Yoshihito
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- Hydrolysis of some imidazole, benzimidazole, and 1,2,3-benzotriazole derivatives according to HPLC and NMR diffusimetry data
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Hydrolysis of 1-mesylimidazole, 1-mesylbenzotriazole, and 1-tosylbenzimidazole was studied by reversed-phase HPLC and pulsed field gradient NMR diffusimetry. The hydrolysis rate constants and half reaction times were determined. The self-diffusion coeffic
- Polyakova,Bulanova,Vartapetyan
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- A kinetic study of acid-catalyzed hydrolysis of some arylsulfonyl phthalimides
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The acid-catalyzed hydrolysis of arylsulfonyl phthalimides was studied in aqueous solutions of sulfuric, perchloric, and hydrochloric acid at 35.0 ± 0.1C. Analysis of the data by the excess acidity method and activation parameters, as well as substituent and solvent isotope effects, indicate hydrolysis by an A-2 mechanism at low acidity. At higher acidities, a changeover to an A-1 mechanism is observed.
- Kutuk, Halil,Ozturk, Seyhan
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- Recyclable imidazolium ion-tagged nickel catalyst for microwave-assisted C-S cross-coupling in water using sulfonyl hydrazide as the sulfur source
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Herein, we report the facile and convenient synthesis of aryl sulfides through the sulfenylation of aryl halides with arylsulfonyl hydrazides, which is catalyzed by a simple and water-soluble Ni(ii) complex. The nickel complex based on the imidazolium ion-tagged salen architecture is synthesized and well characterized using various analytical techniques. The green solvent water is used as the solvent medium and moderate to good yields of aryl sulfides are obtained using 5 mol% of the catalyst under microwave irradiation. The incorporation of the ion-tag functionality helps in the recycling of the catalyst and successful reuse for up to five runs without appreciable change in its activity.
- Saini, Vaishali,Khungar, Bharti
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- Photocleavage of o-nitrobenzyl ether derivatives for rapid biomedical release applications
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The externally controlled cleavage of covalently linked prodrugs, proteins, or solid-phase formulation vehicles offers potential advantages for controlled drug or gene delivery. A series of o-nitrobenzyl ester compounds (1-8) were synthesized to allow a systematic study of photolability. The o-nitrobenzyl ester was strictly required for photolability, while imido esters were not photolabile. The degradation kinetics of 1-o-phenylethyl ester was an order of magnitude faster than that of o-nitrobenzyl ester. Tosylate, phosphate, and benzoate derivatives of 1-o-nitrophenylethyl displayed similar photolability (>80% decomposition within 10 min at 3.5 mW/cm2 at 365 nm). O-o-Nitrobenzyl O′,O″-diethyl phosphate displayed the fastest decomposition at photoirradiation condition (3.5 mW/cm2, 365 nm) suitable for biological systems. We report the synthesis and photo-decomposition of 1-o-nitrophenylethyl derivatives amenable for the creation of photolabile prodrugs or formulation particles for drug depots, DNA condensation, or tissue engineering applications.
- Kim, Moon Suk,Diamond, Scott L.
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- Solvolyses of Secondary Sulfonates in Aqueous Ethanol and Acetone. Nonlinear mY Relationships due to Leaving Group and Medium Effects
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Solvolitic rate constants for secondary mesylates and tosylates in aqueous ethanol and in aqueous acetone are correlated with Winstein-Grunwald Y values.Curvature of these plots is greatest for tosylates in aqueous ethanol, especially for 2-adamantyl.Because mesylates show little or no curvature, it is argued that the results cannot be explained by mechanistic changes but by solvation effects of the leaving group in the mixed solvents.The parameter, m, measuring response to solvent ionizing power varies from 0.68 for isopropyl to 1.21 for 2-adamantyl mesylate in aqueosus acetone at 25 deg C.An alternative solvent ionizing power parameter for tosylates, YOTs , and the solvent nucleohpilicity parameter, NOTs, are evaluated for 20percent ethanol/water, 20percent acetone/water, and 40percent acetone/water.It is proposed that solvolyses of substrates having the same (or very similar) leaving group should be compared if reliable mechanistic information (e.g., nucleophilic solvation effects) is required.The tendency for "dispersion" of correlation lines for various binary mixed solvents appears to be due to both leaving-group effects and to variations in solvent nucleophilicity.By helping to account for curvature and dispersion in mY correlations, this work supports recent work in which mechanistic information was deduced from similar correlations.
- Bentley, William T.,Bowen, Christine T.,Brown, Herbert C.,Chloupek, Frank J.
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- BRANCHED AMINO ACID SURFACTANTS
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The present disclosure provides derivatives of amino acids that have branched alkyl structures and surface-active properties. The amino acid can be naturally-occurring or synthetic, or they may be obtained via a ring-opening reaction of a lactam, such as caprolactam. The amino acid may be functionalized to form a compound that is surface-active and have advantageous surfactant characteristics. The compounds of the present disclosure have low critical micelle concentrations (CMC) as well as superior ability to lower the surface tension of a liquid.
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- Primary Sulfonamide Functionalization via Sulfonyl Pyrroles: Seeing the N?Ts Bond in a Different Light
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Despite common occurrence in molecules of value, methods for transforming sulfonamides are distinctly lacking. Here we introduce easy-to-access sulfonyl pyrroles as synthetic linchpins for sulfonamide functionalization. The versatility of the sulfonyl pyrrole unit is shown by generating a variety of products through chemical, electrochemical and photochemical pathways. Preliminary results on the direct functionalization of primary sulfonamides are also provided, which may lead to new modes of activation.
- Ozaki, Tomoya,Yorimitsu, Hideki,Perry, Gregory J. P.
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p. 15387 - 15391
(2021/10/04)
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- Cornforth and Corey-Suggs reagents as efficient catalysts for sulfonation of aromatic and heteroaromatic compounds using NaHSO3 under solvent free and microwave conditions
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Cornforth and Corey-Suggs reagents Pyridinium Dichromate (PDC) and Pyridinium Chlorochromate (PCC) were explored as efficient catalysts for sulfonation of aromatic and heteroaromatic compounds using NaHSO3 in aqueous acetonitrile medium at room temperature within 1–4 h, while microwave assisted reactions took place within 1–4 min under solvent-free conditions. These observations indicate significant rate accelerations in microwave assisted reactions. which were explained due to the bulk activation of molecules induced by insitu generated high temperatures and pressures when microwaves are transmitted through reaction medium.
- Fatima, Touheeth,Duguta, Govardhan,Purugula, Venkanna,Yelike, Hemanth Sriram,Kamatala, Chinna Rajanna
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p. 1001 - 1006
(2020/07/27)
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- Sustainable access to sulfonic acids from halides and thiourea dioxide with air
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A sustainable and mild one-step strategy is explored for the synthesis of aryl and alkyl sulfonic acids using a facile combination of halides and sulfur dioxide surrogates under air. The cheap industrial material thiourea dioxide was employed as an eco-friendly and easy-handling sulfur dioxide surrogate, while air was used as a green oxidant. Both aryl and alkyl sulfonic acids were obtained under transition metal-catalyzed or transition metal-free conditions. Mechanistic studies demonstrated that sulfinate was involved as an intermediate in this transformation. Notably, this protocol has been applied to the late-stage sulfonation of the drugs naproxen, isoxepac and ibuprofen.
- Zhang, Hui,Wang, Ming,Jiang, Xuefeng
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supporting information
p. 8238 - 8242
(2020/12/29)
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- N,N′-Disulfonylhydrazines: New sulfonylating reagents for highly efficient synthesis of (E)-vinyl sulfones at room temperature
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N,N′-Disulfonylhydrazines have been proven to be the most reactive precursors of sulfonyl radicals in all types of sulfonyl substituted hydrazines as early as a half century ago. But such function has not been applied in organic synthesis except the formation of disulfones by self-dimerization of sulfonyl radicals. In this article, they were introduced as new sulfonylating reagents and their combinations with NIS and Et3N were established as excellent iodosulfonylating reagents for alkenes. Finally, a highly efficient method for the synthesis of (E)-vinyl sulfones was developed by mixing an alkene, a N,N′-disulfonylhydrazine, NIS and Et3N in THF at room temperature for 5 min.
- Hu, Yuefei,Luo, Dongping,Min, Lin,Shan, Lidong,Wang, Xinyan,Zheng, Weiping
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- Aryl and alkyl sulfonic acid compounds as well as construction method adopting inorganic sulfur salt and application
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The invention discloses aryl and alkyl sulfonic acid compounds as shown in a formula (1) and a synthesis method thereof. The method comprises the following step: aromatic iodine and an inorganic sulfur source or alkyl bromide and an inorganic sulfur source as reaction raw materials react in a solvent under the action of alkali, a catalyst or an additive to obtain a series of aryl and alkyl sulfonic acid compounds. According to the method, the aryl and alkyl sulfonic acid compounds are constructed in one step by taking an inorganic sulfur reagent as a sulfur source, so that the defect of the mode in which the aryl and alkyl sulfonic acid compounds are synthesized by taking concentrated sulfuric acid, chlorosulfonic acid or sulfur dioxide gas and the like as sulfonating reagents in the priorart is avoided. The aryl and alkyl sulfonic acid compounds developed by the invention can be used for synthesizing aryl and alkyl sulfonic acid drug analogues.
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Paragraph 0046-0049
(2020/09/16)
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- Synthesis of phenanthridines through iodine-supported intramolecular C-H amination and oxidation under visible light
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Herein, we report a metal-free and step-economic synthesis of phenanthridines from 2-biarylmethanamines under mild conditions. The reaction involves iodine-supported intramolecular C-H amination and oxidation of 5,6-dihydrophenanthridine under air and benign visible light. The mechanism study reveals that visible light plays a key role in both these steps.
- Chen, Xuenian,Ma, Yan-Na,Gao, Yan,Jing, Yi,Li, Lixin,Zhang, Jie
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supporting information
p. 12187 - 12198
(2020/11/10)
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- Selective Late-Stage Sulfonyl Chloride Formation from Sulfonamides Enabled by Pyry-BF4
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Reported here is a simple and practical functionalization of primary sulfonamides, by means of a pyrylium salt (Pyry-BF4), with nucleophiles. This simple reagent activates the poorly nucleophilic NH2 group in a sulfonamide, enabling the formation of one of the best electrophiles in organic synthesis: a sulfonyl chloride. Because of the variety of primary sulfonamides in pharmaceutical contexts, special attention has been focused on the direct conversion of densely functionalized primary sulfonamides by a late-stage formation of the corresponding sulfonyl chloride. A variety of nucleophiles could be engaged in this transformation, thus permitting the synthesis of complex sulfonamides, sulfonates, sulfides, sulfonyl fluorides, and sulfonic acids. The mild reaction conditions and the high selectivity of Pyry-BF4 towards NH2 groups permit the formation of sulfonyl chlorides in a late-stage fashion, tolerating a preponderance of sensitive functionalities.
- Gómez-Palomino, Alejandro,Cornella, Josep
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supporting information
p. 18235 - 18239
(2019/11/13)
-
- Preparation method for p-toluenesulfonic acid
-
The invention relates to a preparation method for p-toluenesulfonic acid, which belongs to the field of organic synthesis. Toluene is pumped into a falling film microstructure reactor through a constant flow pump and produces a contact reaction with an introduced SO3/N2 mixed gas, reacted materials are then introduced into a microchannel reaction tube to continue producing a reaction to obtain a reaction product, and a tail gas is absorbed by utilizing an alkali liquor. The method utilizes the advantages of the falling film microstructure reactor in heat and mass transfer, does not need a catalyst and a solvent to be added, does not generate waste acid, can achieve continuous preparation of the p-toluenesulfonic acid in a short time, and has the advantages of low cost of a device, continuously controllable process, high product purity, easy implementation of industrialization, and the like.
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Paragraph 0016-0020
(2019/04/17)
-
- 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; 0064; 0065; 0066
(2018/03/25)
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- COMPOUNDS FOR THE TREATMENT OF RESPIRATORY DISEASES
-
The present invention relates to new compounds that are useful in the prevention or treatment of respiratory diseases, such as asthma, to the preparation of the compounds, and to compositions including the compounds. The present invention also relates to the use of the compounds, as well as compositions including the compounds, in treating or preventing respiratory diseases.
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Page/Page column 72
(2018/11/26)
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- Coupling of C(sp3)-H bonds with C(sp2)-O electrophiles: mild, general and selective
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Herein is reported the mild and general coupling of amine/ether C(sp3)-H bonds with various kinds of C(sp2)-O electrophiles with high selectivity and efficiency. Valuable allylic/benzylic amines are generated in moderate to excellent yields. The utility of this transformation is demonstrated by a broad substrate scope (>50 examples), good functional group tolerance and facile product modification.
- Gui, Yong-Yuan,Liao, Li-Li,Sun, Liang,Zhang, Zhen,Ye, Jian-Heng,Shen, Guo,Lu, Zhi-Peng,Zhou, Wen-Jun,Yu, Da-Gang
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supporting information
p. 1192 - 1195
(2017/02/05)
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- DSD acid preparation method
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The invention relates to the field of chemical synthesis, in particular to a DSD acid preparation method. The DSD acid preparation method includes the steps that methylbenzene is subjected to sulfonation, purification and separation to obtain OTS, wherein the byproduct is PTS; OTS is subjected to mixed acid nitration to obtain PNTS; PNTS is subjected to chlorine oxidative condensation to obtain DNS; DNS is subjected to catalyzed hydrogeneration reduction to obtain the high-quality target product, namely DSD acid which can be directly used for synthesizing a fluorescent whitening agent. The synthesis method greatly reduces dangerousness of the process, greatly reduces generation of harmful byproducts and waste, particularly, does not generate a lot of carcinogenic intermediate, namely ortho-nitrotoluene, completely solves the nitration safety problem of the old technology, and has the advantages of being simple in step, high in yield and the like.
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Paragraph 0069; 0070
(2017/11/03)
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- Method for achieving pipe-type continuous production of CLT acid nitride
-
The invention discloses a method for achieving pipe-type continuous production of CLT acid nitride. The method comprises the steps that 1, methylbenzene and sulfuric acid conduct a sulfonation reaction in a sulfonation pipe reactor; 2, thth sulfonation reaction solution obtained in the first step and chlorine are continuously fed into a chlorination pipe reactor for a chlorination reaction; 3, the chlorination reaction solution obtained in the second step and nitric acid are continuously fed into a nitrification pipe reactor for a nitrification reaction, and then the CLT acid nitride is prepared. According to the method for achieving pipe-type continuous production of the CLT acid nitride, purification treatment does not need to be conducted on an intermediate in the reaction process, operation is easy, the reaction efficiency is high, and the objective product selectivity is high.
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Paragraph 0061; 0062; 0063; 0064; 0065; 0066
(2016/11/17)
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- Method for producing CLT acid nitride in continuous pipelization mode
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The invention discloses a method for producing CLT acid nitride in a continuous pipelization mode. The method includes the following steps that 1, CLT acid sulphonate and chlorine gas are continuously introduced into a chloridizing pipeline reactor to be subjected to a chlorination reaction; 2, a chlorination reaction solution obtained in the step 1 and nitric acid are continuously introduced into a nitrating pipeline reactor to be subjected to a nitratlon reaction to obtain the CLT acid nitride. In the method, it is unnecessary to purify an intermediate in the reaction process, and the method is easy to operate, high in reaction efficiency and high in target product selectivity.
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Paragraph 0066; 0067; 0068; 0069; 0070; 0071
(2016/12/01)
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- Study of the Paternò–Büchi type photolabile protecting group and application to various acids
-
An efficient photolabile protecting group, thiochromone S,S-dioxides with the diazomethyl group for phosphate derivatives, amino acids and sulfonic acids was developed. Protection and photodeprotection reactions proceeded smoothly under mild conditions without any catalyst.1H NMR and HPLC spectra studies demonstrated the photolysis properties of the photolabile protecting group and gave an exact quantification of the released substrates. Specially, the photoproduct derived from the thiochromone derivatives following Paternò–Büchi type photo-cycloaddition showed high fluorescence intensity. This fluorescent characteristic demonstrated the photodeprotection progress also can be monitored by fluorescence spectra.
- Zhang, Youlai,Zhang, Huan,Ma, Chi,Li, Junru,Nishiyama, Yasuhiro,Tanimoto, Hiroki,Morimoto, Tsumoru,Kakiuchi, Kiyomi
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supporting information
p. 5179 - 5184
(2016/11/13)
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- REDUCTION METHOD OF ARENESULFONAMIDE, PRODUCTION METHOD OF ARENESULFONIC ACID AND BINAPHTHYLDISULFONIC ACID
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PROBLEM TO BE SOLVED: To obtain a corresponding reduction body from an arenesulfonamide with good yields. SOLUTION: A N,N-dimethylnaphthalene-2-sulfonamide is reduced with 5 equivalents of Red-Al (NaAlH2(OC2H4OCH3)2), so that a corresponding sulfinic acid is obtained with good yields. The sulfinic acid is oxidized with oxygen (1 atm), so that a corresponding naphthalene-2-sulfonic acid is obtained. COPYRIGHT: (C)2015,JPO&INPIT
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-
Paragraph 0029; 0031; 0034
(2016/11/17)
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- (METH)ACRYLATE COMPOUND, OPTICAL COMPOSITION, MOLDED ARTICLE, AND OPTICAL ELEMENT
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An optical element including a molded article is provided, the molded article being prepared by molding a polymer prepared by polymerizing a (meth)acrylate compound represented at least by the following general formula (1): wherein a and b are each an integer of 1 or 2; X and Y are each —S— or —O—; R1 and R2 are each an alkyl group having 1 or 2 carbon atoms or a hydrogen atom; and Z1 and Z2 are each an alkyl group having 1 or 2 carbon atoms, having a substituent and represented by the following general formula (2): wherein m is selected from 0 and 1; W is a hydrogen atom or a methyl group; and V is selected from substituents represented by the following: *—O—CnH2n—O—**; *—S—CnH2n—S—**; and *—S—CnH2n—O—**, wherein * represents a bond with an alkyl group; ** represents a bond with a (meth)acryloyl group; n is selected from 2, 3 and 4; and at least one hydrogen atom of —CnH2n— is replaced by a methyl group.
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Page/Page column
(2015/07/02)
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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
-
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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- CuI catalyzed sulfonylation of organozinc reagents with sulfonyl halides
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In this study, a facile CuI catalyzed synthesis of sulfones involving a nucleophilic addition of functionalized organozinc reagents to organic sulfonyl chlorides is realized. This reaction proceeds efficiently at room temperature, giving rise to various functional group substituted sulfones, generally in moderate to high yields. The method provides a novel, simple, and promising strategy for functionalized sulfone synthesis in the research field of sulfur chemistry. the Partner Organisations 2014.
- Fu, Ying,Zhu, Wenbo,Zhao, Xingling,Huegel, Helmut,Wu, Zhouqiang,Su, Yuhu,Du, Zhengyin,Huang, Danfeng,Hu, Yulai
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p. 4295 - 4299
(2014/06/23)
-
- Synthesis and antimicrobial activities of some 6-methyl-3-thioxo-2,3- dihydro-1,2,4-triazine derivatives
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4-Arylidene-imidazole derivatives (4a,b) were readily prepared by reacting 4-am- ino-6-methyl-3-thioxo-2,3-dihydro[1,2,4]triazin-5(4H)-one (1) with 4-arylidene-2-phenyl- 4H-oxazol-5-one (2). Reaction of 1 with some aromatic aldehydes in presence of trieth
- El-Barbary, Ahmed A.,El-Shehawy, Ashraf A.,Abdo, Nabiha I.
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p. 400 - 409
(2014/03/21)
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- Aerobic oxidation in nanomicelles of aryl alkynes, in water at room temperature
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On the basis of the far higher solubility of oxygen gas inside the hydrocarbon core of nanomicelles, metal and peroxide free aerobic oxidation of aryl alkynes to β-ketosulfones has been achieved in water at room temperature. Many examples are offered that illustrate broad functional group tolerance. The overall process is environmentally friendly, documented by the associated low E Factors. It's all happenin' in the micelle! The highly preferential dissolution of oxygen gas within the lipophilic cores inside nanomicelles leads to efficient trapping of in situ generated vinyl radicals. These intermediate radicals, derived from arylalkynes and sulfinic acids, lead to β-ketosulfone products, formed under especially mild and green conditions: no metals, no heating or cooling, recyclable aqueous media, and low E Factors.
- Handa, Sachin,Fennewald, James C.,Lipshutz, Bruce H.
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supporting information
p. 3432 - 3435
(2014/04/03)
-
- Sulfides, sulfones, and sulfoxides of the furan-2(5H)-one series. synthesis and structure
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A number of 4- and 5-R-sulfanylfuran-2(5H)-one derivatives were synthesized, and their oxidation with various reagents was studied. The corresponding sulfones were obtained using hydrogen peroxide in acetic acid. 4-R-sulfanyl derivatives were selectively oxidized to sulfoxides with m-chloroperoxybenzoic acid. The molecular and crystal structures of some new sulfones and sulfoxides were determined by X-ray analysis.
- Latypova,Saigitbatalova, E. Sh.,Chulakova,Lodochnikova,Kurbangalieva,Berdnikov,Chmutova
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p. 521 - 534
(2014/06/10)
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- A trifluoroacetic acid-labile sulfonate protecting group and its use in the synthesis of a near-IR fluorophore
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Sulfonated molecules exhibit high water solubility, a property that is valuable for many biological applications but often complicates their synthesis and purification. Here we report a sulfonate protecting group that is resistant to nucleophilic attack but readily removed with trifluoroacetic acid (TFA). The use of this protecting group improved the synthesis of a sulfonated near-IR fluorophore and the mild deprotection conditions allowed isolation of the product without requiring chromatography.
- Pauff, Steven M.,Miller, Stephen C.
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supporting information
p. 711 - 716
(2013/02/25)
-
- Synthesis of sulfonyl chlorides and sulfonic acids in SDS micelles
-
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)
-
- Synthesis, photophysical and photochemical properties of photoacid generators based on N-hydroxyanthracene-1,9-dicarboxyimide and their application toward modification of silicon surfaces
-
We have introduced a series of nonionic photoacid generators (PAGs) for carboxylic and sulfonic acids based on N-hydroxyanthracene-1,9-dicarboxyimide (HADI). The newly synthesized PAGs exhibited positive solvachromatic emission (λmax(hexane) 461 nm, λmax(ethanol) 505 nm) as a function of solvent polarity. Irradiation of PAGs in acetonitrile (ACN) using UV light above 410 nm resulted in the cleavage of weak Na-O bonds, leading to the generation of carboxylic and sulfonic acids in good quantum and chemical yields. Mechanism for the homolytic Na-O bond cleavage for acid generation was supported by time-dependent density functional theory (TD-DFT) calculations. More importantly, using the PAG monomer N-(p-vinylbenzenesulfonyloxy)anthracene- 1,9-dicarboxyimide (VBSADI), we have synthesized N-(p-vinylbenzenesulfonyloxy) anthracene-1,9-dicarboxyimidea-methyl methacrylate (VBSADI-MMA) and N-(p-vinylbenzenesulfonyloxy)anthracene-1,9-dicarboxyimidea-ethyl acrylate (VBSADI-EA) copolymer through atom transfer radical polymerization (ATRP). Finally, we have also developed photoresponsive organosilicon surfaces using the aforementioned polymers.
- Ikbal, Mohammed,Banerjee, Rakesh,Atta, Sanghamitra,Dhara, Dibakar,Anoop, Anakuthil,Singh, N. D. Pradeep
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p. 10557 - 10567
(2013/02/22)
-
- Direct regioselective esterification at O-2 of β- Cyclodextrin and hydrolysis by neighboring-group participation
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A simple and efficient strategy for direct regioselective esterification at O-2 of β-cyclodextrin was developed by using the combination of N,N?-carbonyldiimidazole and carbonate buffer in 1,4-dioxane, which does not require large amounts of polar organic solvents such as DMF, toxic solvents such as CH3CN, or flammable bases such as NaH. Moreover, their hydrolyses by neighboring-group participation were observed. Mono-2-tosyl- β-cyclodextrin was liable to epoxidation, while mono-2-(p-methylbenzoyl)- β- cyclodextrin liable to isomerization. They had different mechanisms of hydrolysis.
- Wang, Zhi-Zhong,Ma, Xuan-Ping,Wei, Xiao-Gang
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scheme or table
p. 1562 - 1568
(2012/05/21)
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- Development of 1-Hydroxy-2(1H)-quinolone-Based Photoacid Generators and Photoresponsive Polymer Surfaces
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A new class of carboxylate and sulfonate esters of 1-hydroxy-2(1H)- quinolone has been demonstrated as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1-hydroxy-2(1H)-quinolone by UV light (γ≥310 nm) resulted in homolysis of weak N-O bond leading to efficient generation of carboxylic and sulfonic acids, respectively. The mechanism for the homolytic N-O bond cleavage was supported by time-dependent DFT calculations. Photoresponsive 1-(p-styrenesulfonyloxy)-2-quinolone-methyl methacrylate (SSQL-MMA) and 1-(p-styrenesulfonyloxy)-2-quinolone-lauryl acrylate (SSQL-LA) copolymers were synthesized from PAG monomer 1-(p-styrenesulfonyloxy) -2-quinolone, and subsequently controlled surface wettability was demonstrated for the above-mentioned photoresponsive polymers. Copyright
- Ikbal, Mohammed,Banerjee, Rakesh,Atta, Sanghamitra,Jana, Avijit,Dhara, Dibakar,Anoop, Anakuthil,Singh, N. D. Pradeep
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p. 11968 - 11975
(2012/10/29)
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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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- Method for Producing Sodium Chloride-Free Ammonium Nitriles
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This invention relates to a method for producing sodium chloride-free compounds of formula (I), wherein R1, R2, R3 and Z are defined in the description. The method according to the invention is characterized by reacting a tertiary amine of the formula NR1R2R3 with chloroacetonitrile in an organic solvent and then adding an acid of the formula HZ.
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Page/Page column 3
(2009/07/17)
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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
-
scheme or table
p. 799 - 806
(2010/06/16)
-
- 4-SUBSTITUTED-6-ISOPROPYL-BENZENE-1,3-DIOL COMPOUNDS AND THEIR USE
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The present invention pertains generally to the field of therapeutic compounds, and more specifically to certain 4-substituted-6-isopropyl-benzene 1,3-diol compounds (referred to herein as IBD compounds), which, inter alia, inhibit heat shock protein 90 (HSP90) function. The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit HSP90 function, and in the treatment of diseases and conditions that are mediated by HSP90, that are ameliorated by the inhibition of HSP90 function, etc., including proliferative conditions such as cancer, etc.
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Page/Page column 132; 134
(2009/06/27)
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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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- Stereochemistry of 1,2-elimination reactions at the E2-E1cB interface - Tert-butyl 3-tosyloxybutanoate and its thioester
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Experimental data on the stereoselectivity of base-catalyzed 1,2-elimination reactions that produce conjugated carbonyl compounds are scarce in spite of the importance of these reactions in organic and biochemistry. As part of a comprehensive study in this area, we have synthesized stereospecifically-deuterated β-tosyloxybutanoate esters and thioesters and studied the stereoselectivity of their elimination reactions under non-ion pairing conditions. With the availability of both the (2R*,3R*) and (2R*,3S*) diastereomers the innate stereoselectivity could be determined unambiguously. 1H and 2H NMR data show that these substrates produce 5-6% syn elimination, the usual amount for acyclic substrates undergoing E2 reactions. Contrary to earlier suggestions, activation by a carbonyl group has virtually no influence upon the stereoselectivity. Elimination of the (2R*,3R*) diastereomer of the β-tosyloxyester and thioester produces 21-25% of the (Z)-alkene, much more than observed with a poorer β-nucleofuge. A relatively large amount of (Z)-alkene product seems to be a good marker for an E2 pathway, in which the transition state is E1cB-like, rather than an E1cBirrev mechanism. Syn KIE values were higher than those for anti elimination for the esters as well as the thioesters. Experimental challenges to the synthesis of stereospecifically-deuterated β-tosyloxyesters are discussed. The Royal Society of Chemistry 2008.
- Mohrig, Jerry R.,Alberg, David G.,Cartwright, Craig H.,Pflum, Mary Kay H.,Aldrich, Jeffrey S.,Anderson, J. Kyle,Anderson, Shelby R.,Fimmen, Ryan L.,Snover, Amy K.
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experimental part
p. 1641 - 1646
(2008/10/09)
-
- New sources of "active" halogen bis(dialkylamide)hydrogen dibromobromates, efficient reagents for destruction of ecotoxicants
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Bis(dialkylamide)hydrogen dibromobromates were synthesized and their reactivity was investigated in decomposition of diethylphosphonic, diethylphosphoric, and 4-toluenesulfonic acids 4-nitrophenyl esters. The nucleophilic reactivity of a typical α-nucleop
- Prokop'eva,Mikhailov,Turovskaya,Karpichev,Burakov,Savelova,Kapitanov,Popov
-
experimental part
p. 637 - 646
(2009/04/10)
-
- 2-SUBSTITUTED 4-BENZYLPHTHALAZINONE DERIVATIVES AS HISTAMINE H1 AND H3 ANTAGONISTS
-
The present invention relates to compounds of formula (I), and salts thereof, processes for their preparation, to compositions containing them and to their use in the treatment of various disorders, such as allergic rhinitis.
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Page/Page column 73-74
(2008/06/13)
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- Transition-metal-catalyzed carbon-nitrogen and carbon-carbon bond-forming reactions
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One aspect of the present invention relates to ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in various transition-metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition-metal-catalyzed reactions, including the range of suitable substrates, number of catalyst turnovers, reaction conditions, and efficiency. For example, improvements have been realized in transition metal-catalyzed: aryl amination reactions; aryl amidation reactions; Suzuki couplings; and Sonogashira couplings. In certain embodiments, the invention relates to catalysts and methods of using them that operate in aqueous solvent systems.
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Page/Page column 26; Sheet 3
(2008/06/13)
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