- Predicting the hydrolytic breakdown rates of organophosphorus chemical warfare agent simulants using association constants derived from hydrogen bonded complex formation events
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Organophosphorus (OP) chemical warfare agents (CWAs) represent an ongoing global threat, through either purposeful environmental release or the need to dispose of historic stockpiles. This presents a need for the development of novel decontamination technologies. Due to the toxic nature and legal limitations placed on OP CWAs, the use of appropriate OP simulants that mimic the reactivity but not the toxicity of the agents themselves is vital to decontamination studies. Herein, we show that association constants derived from non-specific hydrogen bonded complexation events may be used as parameters within models to predict simulant reactivity. We also discuss the limitations that should be placed on such data.
- Chu, Dominique F.,Clark, Ewan R.,Ellaby, Rebecca J.,Hiscock, Jennifer,Pépés, Antigoni
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- PROCESS FOR PREPARATIONOF GLYCOPYRROLATE TOSYLATE
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Disclosed herein is an efficacious process for preparation of highly purified Glycopyrrolate tosylate in high yield. The process is being cost effective, environment friendly and easily scalable to high volume industrial production.
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Page/Page column 6
(2020/06/01)
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- Method for recycling byproduct p-toluene magnesium sulfonate to synthesize tenofovir
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The invention relates to the technical field of medicine chemicals and in particular discloses a method for recycling a byproduct p-toluene magnesium sulfonate to synthesize tenofovir. According to the method, hydroxymethylphosphonic acid diethyl ester and paratoluensulfonyl chloride are adopted as raw materials, magnesium carbonate is adopted as an acid-binding agent, p-toluenesulfonyl oxymethyldiethyl phosphate is synthesized, tenofovir is synthesized from the p-toluenesulfonyl oxymethyl diethyl phosphate and R-9-(2-hydroxypropyl), and meanwhile, a byproduct p-toluene magnesium sulfonate isgenerated; and magnesium carbonate and sodium p-toluenesulfonate are generated through a reaction of the p-toluene magnesium sulfonate and sodium carbonate. According to the method, the byproduct p-toluene magnesium sulfonate is mainly recycled, process treatment difficulties are reduced, byproducts p-toluene magnesium sulfonate and magnesium chloride which are obtained after treatment are high in purity, export sales can be achieved, the magnesium carbonate can be applied to synthesis of the p-toluenesulfonyl oxymethyl diethyl phosphate, and the production cost can be reduced.
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Paragraph 0035; 0036
(2019/10/01)
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- Norbornene probes for the study of cysteine oxidation
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Cysteine residues on proteins can react with cellular oxidants such as hydrogen peroxide. While this process is important for scavenging excess reactive oxygen species, the products of this oxidation may also mediate cell signalling. To understand the role of cysteine oxidation in biology, selective probes are required to detect and quantify its occurrence. Cysteine oxidation products such as sulfenic acids are sometimes unstable and therefore short-lived. If such cysteine derivatives are to be analysed, rapid reaction with the probe is required. Here we introduce norbornene derivatives as probes for cysteine oxidation, and demonstrate their ability to trap sulfenic acids. The synthesis of norbornene derivatives containing alkyne or biotin affinity tags are also reported to facilitate the use of these probes in chemical biology and proteomics.
- Alcock, Lisa J.,Farrell, Kyle D.,Akol, Mawey T.,Jones, Gregory H.,Tierney, Matthew M.,Kramer, Holger B.,Pukala, Tara L.,Bernardes, Gon?alo J.L.,Perkins, Michael V.,Chalker, Justin M.
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supporting information
p. 1220 - 1228
(2017/11/27)
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- Profiling sulfonate ester stability: Identification of complementary protecting groups for sulfonates
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(Figure presented) Sulfonation is prized for its ability to impart water-solubility to hydrophobic molecules such as dyes. This modification is usually performed as a final step, since sulfonated molecules are poorly soluble in most organic solvents, which complicates their synthesis and purification. This work compares the intrinsic lability of different sulfonate esters, identifying new sulfonate protecting groups and mild, selective cleavage conditions.
- Miller, Stephen C.
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scheme or table
p. 4632 - 4635
(2010/09/17)
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- Removal of alkyl alkanesulfonate esters from alkanesulfonic acids and other organic media
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Methods of removing alkyl alkanesulfonate esters from aqueous or anhydrous compositions are provided. The invention provides methods for the conversion of alkyl alkanesulfonate esters of the formula RSO3R′ to the corresponding acids of the formula RSO3H. The alkyl alkanesulfonate esters are present in an organic medium, which may contain significant amounts of water or which may be anhydrous or substantially anhydrous. In some embodiments, the invention provides methods for purifying aqueous or anhydrous alkanesulfonic acids by removing alkyl alkanesulfonate esters.
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Page/Page column 6; 7
(2008/06/13)
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- Bis-phosphonate confugates with alkylating moieties having antitumor activity
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The present invention relates to conjugates of 3-carboxy-4,4′-dihydroxyphosphorylbutenoic acids with alkylating agents, derivatives are endowed with marked antitumor activity, especially against multiple myeloma. The present invention relates as well to a process for the preparation thereof and to pharmaceutical compositions containing them.
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- Synthesis of 3-chloro-Δ3-cephem-4-carboxylate by addition/cyclization of allenecarboxylate. Copper(II)-promoted aerobic oxidation of arenesulfinic acids
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The selective transformation of allenecarboxylate derived from penicillin into 3-chloro-Δ3-cephem-4-carboxylate was successfully achieved by an addition/cyclization reaction with chloride salts in aerobic media containing a copper(II) catalyst, in which copper(II)-catalyzed aerobic oxidation of in situ generated benzenesulfinate ion into less nucleophilic sulfonate ion prior to the nucleophilic addition of the former ion to the allenecarboxylate would completely eliminate the formation of undesired 3-phenylsulfonyl-Δ3-cephem-4-carboxylate. Under similar aerobic conditions, arenesulfinates salts and arenesulfinic acids were smoothly oxidized to the corresponding sulfonate salts and sulfonic acids, respectively.
- Tanaka, Hideo,Kikuchi, Ryo,Torii, Sigeru
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p. 1391 - 1396
(2007/10/03)
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- Thienothiadiazine sulfonamides useful as carbonic anhydrase inhibitors
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New thienothiadiazine sulfonamides useful as carbonic anhydrase inhibitors are disclosed. Methods for using the compounds to control IOP are also disclosed.
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- Synthesis of Aromatic and Olefinic Sodium Sulfonates by Electrophilic Destannylation with Trimethylsilyl Chlorosulfonate
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A mild and effective method for the preparation of a variety of aromatic, olefinic, and acetylenic sodium sulfonates is described.The reaction of trialkylaryl- (2a-k) and -heteroarylstannanes (4a-d), bis-(1-alkenyl)dibutylstannanes (6a-f), or trialkylakynylstannanes with trimethylsilyl chlorosulfonate (1) followed by hydrolysis with aqueous NaHCO3 provides the sodium sulfonates in an ipso-specific and in the case of vinylic stannanes stereospecific manner.A comparision of the reactivity of stannylated and silylated olefinic compounds 13 and 14 underlines the greater leaving ability of the stannyl moiety.The in situ preparation of the stannanes makes it possible to apply the synthetic method to natural products such as N-substituted apocodeine (17). - Key Words: Electrophilic aromatic substitution/ Electrophilic vinylic substitution/ Trialkylstannanes, application of/ Arylsulfonates, sodium salts of/ Vinylsulfonates, sodium salts of
- Niestroj, Michael,Lube, Andreas,Neumann, Wilhelm P.
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p. 575 - 580
(2007/10/02)
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- Organosilylalkylaromatic compounds
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The present invention relates to compounds of the formula STR1 in which Y represents an organosilicon radical; R" represents a divalent radical which connects the radical Y to the benzene ring via a chain of at least three atoms; X represents a radical of the formula --COOH, --CN, --CHO, --NH2 or --OH, in which it is possible to block the hydroxyl group with a protecting group; Z represents the same or different substituents in the 2-, 3-, 5- or 6-position to the radical X, preferably hydrogen or halogen atoms; and p represents a value of 0 to 4; and the use of these and related compounds in the preparation of compounds having liquid-crystalline properties.
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- Tin for Organic Synthesis, 7. New Regioselective Syntheses of Diaryl Sulfones, Arenesulfonamides, and Arenesulfonic Acid Sodium Salts
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The reaction of (trialkylstannyl)arenes 1 with corresponding reagents containing a chlorosulfonyl group leads, by exclusive ipso substitution, to important diaryl sulfones 2a - i, N-alkylarenesulfonamides 8a - f, and sodium arenesulfonates 13a - c in high yields under mild conditions.The specific leaving ability of the stannyl group allows, moreover, the preparation of arylsulfonyl isomers which are not accessible under the influence of the conventional directing forces of substituents.With N,N-dialkylamidosulfonyl chloride / AlCl3 complexes no destannylation takes place, but the first intramolecular sulfonyltin complex 11 is formed.This result is used to discuss details of the mechanism involved. Key Words: Aromatic substitution, electrophilic / Sulfones, synthesis of / Sulfonamides, synthesis of / Sulfonic acids, sodium salts, synthesis of/ Stannanes, trialkylaryl-, application of
- Neumann, Wilhelm P.,Wicenec, Christian
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p. 763 - 768
(2007/10/02)
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- Preparation of diaryliodonium salt photoinitiators having long chain ester groups concatenated with aryl groups
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A highcarbon-containing diaryliodonium initiator for cationic polymerization which possesses enhanced solubility characteristics over conventional diaryliodonium initiators. By the disclosed process, a novel photo/thermal initiator is obtained which is uniquely characterized by the concatenation of a long chain ester with an aryl group, resulting in a total number of carbon atoms in the entire moiety attached to the iodine atom in excess of 20.
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- High yield synthesis of hydroxyl-containing cationic photoinitiators
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Synthesis use of a new class of diaryliodonium salt photo and thermal polymerization initiators in which the aryl groups are substituted with alkoxy group bearing hydroxy groups. Good to excellent yields are obtained of diaryliodonium salts in which the aryl groups are substituted with long chain alkoxy groups, which alkoxy groups also possess at least one hydroxyl moiety attached at the 2-position of an alkoxy group. The resultant salts have enhanced solubility when compared with their lower molecular weight counterparts. The hydroxyl groups serve as chain transfer agents; and, in cross linking UV-induced cationic polymerizations, the hydroxyl groups effect marked accelertion on polymerization rates. The salts also have excellent compatability with nonpolar monomers such as epoxidized oil and poly(1,2-butadience oxide) and provide further benefits when they are used along with copper cocatalysts in thermally curable polymer systems. In the latter form of cases, the secondary hydroxyl group serves as a reducing agent for the copper (II) complex.
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- Transition-metal complexes of superstructured cyclidene macrobicycles: Structural features and their chemical consequences. 3. Cyclidenes with long polymethylene bridges
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The syntheses and X-ray structure determinations are reported for lacunar cyclidene complexes bridged by -(CH2)9- (9) and -(CH2)10- (10) chains. Correlation of these results with those for -(CH2)8- and -(CH2)12- bridges show how the transformations from the flat cavity increasing in width from -(CH2)3- through -(CH2)8- to the tall narrow cavity for -(CH2)12- takes place through graduated conformational changes at the nitrogen atoms to which the bridging groups are attached. These changes can also be observed in 13C NMR spectra, demonstrating that conformations are present in solution similar to those found in the solid state. Correlation of 13C chemical shift with chain length over the range -(CH2)n- (n = 3-10, 12) shows that some resonances are strongly influenced by cavity width. Other resonances show a small-scale alternation between n-odd and n-even, associated with the distortions required in bridges formed from even-membered chains. Crystal data: C29H50N6P2F12Ni.C 3H6O (9), triclinic, P1, a = 11.298 (6) ?, b = 13.615 (9) ?, c = 14.608 (10) ?, α = 75.48 (5)°, β = 73.32 (5)°, γ = 73.56 (5)°, Z = 2; C30H52N6P2F12Ni.C 2H3N (10), orthorhombic, P212121, a = 10.221 (4) ?, b = 13.723 (11) ?, c = 29.255 (16) ?, Z = 4.
- Alcock, Nathaniel W.,Padolik, Peter A.,Pike, Graham A.,Kojima, Masaaki,Cairns, Colin J.,Busch, Daryle H.
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p. 2599 - 2607
(2008/10/08)
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- Kinetic Studies on the Influence of Micellar Aggregates upon the Hydrolysis and Transnitrosation Reactions of N-methyl-N-nitrosotoluene-p-sulphonamide
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The basic hydrolysis of N-methyl-N-nitrosotoluene-p-sulphonamide and its transnitrosation reaction with secondary amines (sarcosine and dimethylamine) have been studied in the presence of cationic, anionic, and non-ionic micelles.The results show that the electric charge of the nucleophile is essential for the understanding of the micellar effects, which can be quantitatively rationalized on the basis of the pseudophase kinetic model.Thus the reaction with negatively charged nucleophiles is inhibited by both anionic and non-ionic surfactants, whereas cationic micelles increase the reaction rate, which passes through a maximum.The reaction between the substrate and a neutral nucleophile is, however, inhibited by all three classes of surfactant.
- Castro, Albino,Leis, J. Ramon,Pena, M. Elena
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p. 1221 - 1225
(2007/10/02)
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- Micellar Effects upon the Rates of SN2 Reactions of Halide Ions
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Observed first-order rate constants for reactions of Cl- or Br- with alkyl benzenesulfonate (1a-c) in micelles of cetyltrimethylammonium surfactants (CTAX, X=Cl, Br, OMes, 0.5SO4) increase monotonically with increasing or or halide ion concentration and tend to limiting values.In CTAOMes or (CTA)2SO4, the rate constants go through maxima.The variation of the rate constants with concentrations of surfactant and halide ion can be fitted to an equation that accounts for the distribution of both reactants between water and micelles, i. e., in terms of ion-exchange and mass-action models.The second-order rate constants in the aqueous and micellar pseudophases are similar.
- Al-Lohedan, Hamad A.
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p. 8226 - 8231
(2007/10/02)
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- Pathways in the Reactions of Nitronate Ions with Sulphonyl Halides
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Primary and tertiary nitronate ions and sulphonyl bromides and iodides rapidly equilibrate with the nitrohalides and sulphinate ion.Products are determined by solvent and by the occurence of cross-equilibrum reactions, some of which have single-electron-transfer mechanism.The reaction of arene-sulphinate and thiolate ions with 1,2-dibromo-2-nitro-1-phenylethane gave E-β-nitrostyrene by Z-philic elimination in both cases, but the more basic thiolate ion also gave, by protophilic elimination, 2-bromo-2-nitro-1-phenylethene.
- Pigou, Paul E.,Stirling, Charles J. M.
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p. 725 - 730
(2007/10/02)
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- Enolate Structures Contributing to the Transition State for Nucleophilic Substitution on α-Substituted Carbonyl Compounds
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The high SN2 reactivity of α-halocarbonyl compounds is explained by the lowering of the intrinsic barrier by a major contribution of enolate structure to the transition state.This theoretical conclusion is now shown experimentally.The evidence is as follows: (1) Change in structure of a leaving arenesulfonate ion does not change the rates of attack of benzenesulfonate ion by nearly as much as it changes the equilibrium constants.A charge on the transferring phenacyl group of -0.48 is deduced. (2) The ρ value (-3.9) for attack of substituted thiophenoxides on phenacyl bromide is much more negative than that for attack on methyl iodide (-1.8). (3) A related ρ value is found for reaction of 2,4,6-trimethylphenacyl bromide with thiophenoxides (-2.2), showing a lesser, but still large sensitivity to nucleophile structure where addition to the carbonyl is sterically forbidden.The enolate structure leaves the attacking or leaving nucleophiles with a single electron each instead of the unshared pairs.Thus, the enolate structure is emphesized if the leaving group and the nucleophile readily lose an electron.
- Yousaf, T. I.,Lewis, E. S.
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p. 6137 - 6142
(2007/10/02)
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- Bromonitromethane. A Versatile Electrophile
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Pathways in reactions of bromonitromethane with a variety of nucleophiles have been investigated.With thiolates, the electrophilic centre is bromine and the initial products are disulphides.When the thiolate ion itself carries an electrophilic centre such as carbonyl or cyano β-to sulphur, the product is a nitrothiophene derived from subsequent reaction of the first-formed disulphide with nitronate ion displaced in the initial process.This provides a generalisation of earlier nitrothiophene synthesis by this route.In reactions with arenesulphinate ion, the electrophilic centre is also bromine and equilibration between the initial reactants and the initial products, sulphonyl bromide and nitronate ion, is established.The components of the equilibrium subsequently react either with each other or with the solvent.Reactions with sulphides are slow and distal substituents such as hydroxy- or cyano- so much reduce reactivity that no reaction is observed.Dimethyl sulfide attacks bromonitromethane at the carbon atom,and subsequent attack on the nitromethyl sulphonium salt initially formed gives methylthionitromethane and trimethylsulphonium bromide.Iodide ion attacks at bromine to give iodine, presumably via iodine bromide, but with tervalent phosphorus nucleophiles, attack is at oxygen giving the corresponding oxides and HCN in a double deoxygenation sequence.For hydroxide, methoxide and hydride ions (from sodium borohydride), nucleophilic attack is at hydrogen and the nitronate ion produced is inert to further attack.There is no evidence of carbene formation by α-elimination.When the anion of bromonitromethane is allowed to react with tributylboron, the anionic migration-displacement which follows boron-carbon bond formation, yields 1-nitropentane.The anion of bromonitromethane is unreactive towards aldehydes and electrophilic alkenes.
- Fishwick, Brian R.,Rowles, David K.,Stirling, Charles J. M.
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p. 1171 - 1180
(2007/10/02)
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- SYNTHESIS AND PROPERTIES OF WATER-SOLUBLE BIS-PARACYCLOPHANES
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Novel water-soluble bis-paracyclophanes (5, 6, 7) were synthesized and their properties as hosts having two independent binding sites were studied.Examples are presented in which a guest molecule having two aromatic rings forms a complex by binding at two sites cooperatively, when host and guest are complementary.
- Lai, Chung-Fang,Odashima, Kazunori,Koga, Kenji
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p. 5179 - 5182
(2007/10/02)
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- Micellar Effects on the Reaction of (Arylsulfonyl)alkyl Arenesulfonates with Hydroxide Ion. Microenvironmental and Substituent Effects in the Stern Layer of Cationic Micelles
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The reaction of the sulfonates p-XC6H4SO2CH(R)OSO2C6H4Y-p 1a-g with hydroxide ion (involving nucleophilic attack at sulfonate sulfur) is accelerated (7-25 times) in the presence of CTAB micelles (32.1 deg C).The kinetic data are analyzed in detail by using the pseudophase ion-exchange (PPIE) model, taking into account partitioning of the reactants between the micellar and aqueous pseudophases and competition between hydroxide ions and detergent counterions for binding to the micelles.Binding constants obtained from the kinetic analysis are compared with those from ultrafiltration experiments.Generally, the PPIE model reproduces the experimental rate constants quite well, except at low detergent concentration (around the cmc).The second-order rate constants for reaction in the micellar pseudophase are 4-12 times smaller than those for reaction in bulk water.Therefore the observed catalysis is purely the result of the high local concentration of both reactants in the micellar pseudophase.The substituent effects for the reaction in the micelles reveal an increased susceptibility for variation of Y.No evidence for orientational effects was found.It is shown that the binding of the sulfonates with the micelles is mainly determined by the presence of the aryl groups.Based on a comparison with kinetic solvent effects on the reaction in 1,4-dioxane-water, it is suggested that the rates in the micellar pseudophase reflect a decrease in micropolarity at the binding sites of the substrate molecules.
- van de Langkruis, Gerard B.,Engberts, Jan B. F. N.
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p. 4152 - 4157
(2007/10/02)
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- Synthesis of thienamycin from D-glucose
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Disclosed is a chiral, total synthesis of thienamycin from D-glucose which proceeds via intermediates I, II and III to known aldehyde IV which is known to be useful in the total synthesis of thienamycin (V): STR1 wherein: R is lower alkyl having 1-6 carbon atoms or bi-valent alkyl having 2-6 carbon atoms which joins the two sulfur atoms; R1 is lower alkyl or aralkyl, such as benzyl and the like; and R2 is hydrogen or a removable protecting group, such as triorganosilyl wherein the organo groups are independently selected from lower alkyl, phenyl and phenylloweralkyl.
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- 3-Amino-4-C-carboxy-2,3,4,6-tetradeoxy-D-arabino-hexose trimethylene dithioacetal
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Disclosed is a chiral, total synthesis of thienamycin from D-glucose, which proceeds via intermediates I, II, and III and joins aldehyde IV or acid V, which are known to be useful in the total synthesis of thienamycin (VI): STR1 wherein R1 is hydrogen or a removable protecting group; R is lower alkyl having 1-6 carbon atoms or bi-valent alkyl having 2-6 carbon atoms which joins the two sulfur atoms.
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- Methyl 3-azido-4-C-cyano-2,3,4,6-tetradeoxy-α-D-arabino-hexopyranoside
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Disclosed is methyl 3-azido-4-C-cyano-2,3,4,6-tetradeoxy-α-D-arabino-hexopyranoside and processes for its preparation from methyl 3-azido-2,3,6-trideoxy-α-D-arabino-hexopyranoside via the 4-bromo-4-deoxy intermediate; wherein the two inversions of configuration at C-4 result in a net retention of the α-D-arabino stereochemistry.
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- DIRECT REDUCTION OF SULFONIC ACID TO THE CORRESPONDING THIOL WITH TRIFLUOROACETIC ANHYDRIDE/TETRABUTYLAMMONIUM IODIDE SYSTEM
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Arene- and alkane-sulfonic acids were easily reduced to the corresponding thiol derivatives in moderate yields with trifluoroacetic anhidride/tetrabutylammonium iodide mixture at room temperature.
- Numata Tatsuo,,Awano Hiroshi,,Oae Shigeru
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p. 1235 - 1238
(2007/10/02)
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- Water-soluble, non-ionizing, radiopaque compounds and contrast compositions containing the same
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α, ω-BIS-[5-(DIHYDROXYALKYL) AMINOCARBONYL-3-HYDROXYACYL-AMINO-2,4,6-TRIIODO-BENZOYL-AMINO]-OXAALKANE COMPOUNDS OF THE FORMULA STR1 wherein R1 is STR2 R and R' are hydrogen or methyl, R2 is dihydroxyalkyl having 3 or 4 carbon atoms, N is 2 or 3, M is an integer between 1 and 5, and N(m+1) is an integer between 4 and 12, Are readily soluble in water to yield injectable radiopaque contrast compositions which are well tolerated and stable. The compounds are prepared in good yields by reacting a reactive derivative of a 5-(di-hydroxyalkyl)aminocarbonyl-3-acyloxyacylamino-2,4,6-triiodo-benzoic acid with an α,ω-diamino-oxaalkane of the formula
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- Substituted 5-phenyl-2,3,4,5-tetrahydro-1,4-benzoxazepines
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Substituted 5-phenyl-2,3,4,5-tetrahydro-1,4-benzoxazepines of the formula STR1 wherein R1 and R2 are each methyl or, when taken together with the nitrogen to which they are attached, represent pyrrolidino, R3 and R4 are the same or different and represent hydrogen, chloro, fluoro, bromo, iodo, nitro, (lower)alkyl, trifluoromethyl, (lower)alkoxy, trifluoromethoxy or (lower)alkylthio, and n is an integer from 1 to 4, and their nontoxic pharmaceutically acceptable acid addition salts, are valuable analgesic and/or antitussive agents.
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- Butirosin A 3",5"-O-isopropylidene derivatives
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3'-Deoxybutirosin A (3'-deoxyambutyrosin A), which is prepared from butirosin A, possesses an improved antibacterial spectra, especially against butirosin A resistant organisms.
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