- TIN(IV) MEDIATED SYNTHESIS OF N-HALO COMPOUNDS
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Some representative N-halo compounds like N-bromosuccinimide, N-iodosuccinimide, N-bromophthalimide, N-iodophthalimide, N-iodobenzimidazole and N-iodobenzotriazole have been synthesised in good yields under neutral and mild conditions via an intermediate formed from the parent NH species and bis(tri-n-butyltin) oxide.The tin oxide is recovered as recyclable tri-n-butyltin halide.
- Soundararajan, R.,Krishnamurthy, S.,Srinivasan, Vilanoor S.,Balasubramanian, T.R.
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- Organic Synthesis Using Sodium Bromate. II. A Facile Synthesis of N-Bromo Imides and Amides Using Sodium Bromate and Hydrobromic Acid (or Sodium Bromide) in the Presence of Sulfuric Acid
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The reaction of imides and amides in water (or aqueous acetic acid) with sodium bromate and hydrobromic acid (or sodium bromide) in the presence of sulfuric acid under mild conditions gave the corresponding N-bromides in high yields.
- Fujisaki, Shizuo,Hamura, Satoshi,Eguchi, Hisao,Nishida, Akiko
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- One-Electron Reduction of N-Bromosuccinimide. Rapid Expulsion of a Bromine Atom
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By means of pulse radiolysis N-bromosuccinimide, SBr, was reduced to its radical anion, SBr?-. Evidence is presented that SBr?- rapidly fragments into the succinimide anion, S-, and a free bromine atom, Br?, which is converted into Br2?- by reacting with Br- present. The rate constant of hydrogen abstraction by Br? from 2-propanol and methanol have been determined. The carbon-centered radical of tert-butyl alcohol was also found to react with SBr yielding Br2?- in the presence of Br-.
- Lind, Johan,Shen, Xinhua,Eriksen, Trygve E.,Merényi, Gábor,Eberson, Lennart
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- A Practical Synthesis of N-Bromo Imides by Use of Sodium Bromite
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N-Bromo imides can be readily prepared under mild conditions by a reaction of imides with sodium bromite in the presence of hydrobromic acid in fairly good yields.The scope and limitation are also presented.
- Kajigaeshi, Shoji,Nakagawa, Takashi,Fujisaki, Shizuo,Nishida, Akiko
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- Triptycenyl Sulfide: A Practical and Active Catalyst for Electrophilic Aromatic Halogenation Using N-Halosuccinimides
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A Lewis base catalyst Trip-SMe (Trip = triptycenyl) for electrophilic aromatic halogenation using N-halosuccinimides (NXS) is introduced. In the presence of an appropriate activator (as a noncoordinating-anion source), a series of unactivated aromatic compounds were halogenated at ambient temperature using NXS. This catalytic system was applicable to transformations that are currently unachievable except for the use of Br2 or Cl2: e.g., multihalogenation of naphthalene, regioselective bromination of BINOL, etc. Controlled experiments revealed that the triptycenyl substituent exerts a crucial role for the catalytic activity, and kinetic experiments implied the occurrence of a sulfonium salt [Trip-S(Me)Br][SbF6] as an active species. Compared to simple dialkyl sulfides, Trip-SMe exhibited a significant charge-separated ion pair character within the halonium complex whose structural information was obtained by the single-crystal X-ray analysis. A preliminary computational study disclosed that the πsystem of the triptycenyl functionality is a key motif to consolidate the enhancement of electrophilicity.
- Nishii, Yuji,Ikeda, Mitsuhiro,Hayashi, Yoshihiro,Kawauchi, Susumu,Miura, Masahiro
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supporting information
p. 1621 - 1629
(2020/02/04)
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- Thiourea-Mediated Halogenation of Alcohols
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The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
- Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
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p. 12901 - 12911
(2020/11/26)
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- Esterification of aryl/alkyl acids catalysed by n-bromosuccinimide under mild reaction conditions
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N-halosuccinimides (NXSs) are well-known to be convenient, easily manipulable and low-priced halogenation reagents in organic synthesis. In the present work, N-bromosuccinimide (NBS) has been promoted as the most efficient and selective catalyst among the NXSs in the reaction of direct esterification of aryl and alkyl carboxylic acids. Comprehensive esterification of substituted benzoic acids, mono-, di- and tri-carboxy alkyl derivatives has been performed under neat reaction conditions. The method is metal-free, air- and moisture-tolerant, allowing for a simple synthetic and isolation procedure as well as the large-scale synthesis of aromatic and alkyl esters with yields up to 100%. Protocol for the recycling of the catalyst has been proposed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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- Preparation method of 2-amino-5-bromopyridine
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The invention discloses a preparation method of 2-amino-5-bromopyridine. The preparation method is characterized in that 2-aminopyridine is used as the raw material, and two different bromination agents, namely bromine and N-bromo-succinimide (NBS), are sequentially added; the reaction temperature is strictly controlled, and thus 2-amino-5-bromopyridine can be quickly prepared with high yield andhigh purity; and the preparation method is applicable to industrial production. Additionally, a high-purity by-product, namely succinimide, is separated out in the preparation process and is brominated into high-purity NBS through potassium bromide, potassium bromate and sulfuric acid; and the NBS is applied to the synthesizing of 2-amino-5-bromopyridine in the method and has the same effect as the commercial NBS. According to the method, the quantity of used NBS is decreased, the raw material conversion rate is increased, and the bromination agents are recycled, so that the cost is greatly decreased; the main byproduct is only inorganic salt potassium sulfate; and the synthesizing method is green and environmentally friendly.
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Paragraph 0018; 0020; 0022
(2018/04/01)
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- Pollution-free preparation method of N-bromosuccinimide
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The invention discloses a pollution-free preparation method of N-bromosuccinimide. The preparation method comprises the following steps that 1, 1 mol of succinimide and 1.02-1.15 mol of sodium bromide are dissolved into 350 ml of water; 2, 1.0-1.13 mol of sodium hypochlorite and 1.03-1.16 mol of diluted hydrochloric acid are dropwise added while the reaction solution is stirred; 3, after dropwise adding is completed, the reaction solution is subjected to standing for 0.8-1.2 hours for reacting; 4, the reaction solution is stirred, cooled to 0 DEG C to 10 DEG C and then subjected to heat preservation and suction filtration, and a crude product is obtained; 5, the crude product is washed with ice water and dried, and N-bromosuccinimide is obtained. The pollution-free preparation method has the advantages that sodium hypochlorite and sodium bromide which are cheap and easy to obtain are utilized as bromine sources, the reaction is gentle and easy to control, the yield is high, the cost is low, and the technology is green and friendly to environment; usage of bromine which is high in toxicity, volatile and expensive in a traditional technology is avoided, and usage of high-cost sodium bromate in an improved technology is avoided.
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Paragraph 0011
(2017/08/27)
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- PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
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The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.
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Paragraph 00114-00115
(2017/07/28)
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- Electrophilic aryl-halogenation using N-halosuccinimides under ball-milling
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We report here a methodology of chemo- and regio-selective aryl bromination and iodination using respective N-halosuccinimides at room temperature in the absence of any solvents, catalyst/additives under ball-milling condition. However, for chlorination ceric ammonium nitrate was used as additive. The coupled product succinimide, produced from the reactions, was recycled via regeneration of NBS. This methodology works with the electron-donor substituted or unsubstituted arenes.
- Bose, Anima,Mal, Prasenjit
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p. 2154 - 2156
(2014/04/03)
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- Efficient aziridination of olefins catalyzed by dirhodium catalysts
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This invention relates to compositions and methods for achieving the efficient aziridination of organic molecules, especially olefins. More specifically, the invention is directed to a mild, selective, and efficient aziridination protocol that involves catalysis by a mixed-valent dirhodium(II,III) catalyst (Rh25+). Especially preferred sources for forming such mixed-valent dirhodium(II,III) catalyst (Rh25+) are dirhodium(II) carboxamidates, such as dirhodium(II) caprolactamate, and their derivatives and analogues.
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Page/Page column 14
(2010/11/23)
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- Conversion of nucleophilic halides to electrophilic halides: Efficient and selective halogenation of azinones, amides, and carbonyl compounds using metal halide/lead tetraacetate
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AlCl3/Pb(OAc)4 and ZnBr2/Pb(OAc) 4 are efficient electrophilic N- and α-C-halogenating agents. A variety of azinones, amides and carbonyl compounds were chemoselectively and regioselectively N-, or α-C-halogenated in good to excellent yield using AlCl3/Pb(OAc)4 and ZnBr2/Pb(OAc)4 in acetonitrile. Georg Thieme Verlag Stuttgart.
- Kim, Jeum-Jong,Kweon, Deok-Heon,Cho, Su-Dong,Kim, Ho-Kyun,Lee, Sang-Gyeong,Yoon, Yong-Jin
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p. 194 - 200
(2007/10/03)
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- PIPERIDINYL-AND PIPERAZINYL-SULFONYLMETHYL HYDROXAMIC ACIDS AND THEIR USE AS PROTEASE INHIBITORS
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This invention is directed generally to proteinase (also known as "protease”) inhibitors, and, more particularly, to piperidinyl-and piperazinyl-sulfonylmethyl hydroxamic acids that, inter alia, inhibit matrix metalloproteinase (also known as "matrix metalloprotease” or "MMP”) activity and/or aggrecanase activity. Such hydroxamic acids generally correspond in structure to the following formula: (wherein A1, A2, Y, E1, E2, E 3, and Rx are as defined in this specification), and further include salts of such compounds. This invention also is directed to compositions of such hydroxamic acids, intermediates for the syntheses of such hydroxamic acids, methods for making such hydroxamic acids, and methods for treating conditions (particularly pathological conditions) associated with MMP activity and/or aggrecanase activity. "
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- Processes, apparatus, and treatment agent/composition for devolatizing and stabilizing vaporous pollutants and their sources
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Processes for controlling pollution by: (a) devolatizing vapor phase chemical pollutants (VP's) found in effluents and other bodies and streams of gases and liquids, and (b) stabilizing substrates from which the VP's are released. The offending VP's are converted to less offensive or inoffensive materials by interaction with an appropriately formulated treating agent (VTA/C) containing a primary halogen and at least one additional ingredient selected from the following classes of constituents (optional if bromine is the primary halogen and otherwise required): oligodynamically active metals, cohalogens, adjuncts, and facilitators. The major constituent(s) may be supplied as such, or a source of the constituent may be provided. Actinic radiation can be employed to promote reactions between the VP and the VTA/C, which is often formulated as an aqueous scrubbing medium. The VTA/C may, however, be employed in other ways-for example: (a) by gaseous infusion into a reaction zone; (b) by dusting or coating the treating agent onto, or otherwise directly adding it to, a substrate prone to evolve VP's to control the emission of VP's from the substrate; or (c) by impregnating it into an activated carbon carrier.
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- Microbicides
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Compounds of formula I STR1 and possible isomers and isomeric mixtures thereof, wherein a) X is CH2 F or CHF2 ; Y is CH and Z is OMe, or b) X is CH2 F or CHF2 ; Y is a nitrogen atom and Z is OMe or NHCH3, and wherein also m is 0, 1, 2, 3, 4 or 5 and U represents identical or different substituents selected from halogen, cyano, nitro, C1 -C12 alkyl, C3 -C8 cycloalkyl, C3 -C6 alkenyl, C3 -C6 alkenyloxyiminomethyl, C1 -C4 alkoxy, C1 -C4 alkoxyiminomethyl, C1 -C2 haloalkyl, C1 -C2 haloalkoxy, unsubstituted or substituted phenyl, unsubstituted or substituted phenoxy and unsubstituted or substituted benzyl or represents substituents at two adjacent positions of the phenyl ring of formula I that define a fused hydrocarbon bridge so as to form a larger hydrocarbon ring having up to 14 carbon atoms, are suitable for controlling and preventing microorganisms, insects and Acarina on plants. They can be used in the form of commercially customary formulated compositions.
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- Biphenyl derivatives and their use for the treatment of hypertension and cardiac disease
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Compounds of formula (I): STR1 [wherein: A represents a group (IIa), (IIb) or (IIc): STR2 R 1 is alkyl, alkenyl, cycloalkyl or a group of formula R 4 --Y--R 5 --, where: R 4 is hydrogen, alkyl, or cycloalkyl, R 5 is a single bond or alkylene, and Y is oxygen, sulfur or imino group; R 2 is hydrogen, halogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, hydroxy, amino, alkylamino, dialkylamino, formyl, alkylcarbonyl, alkoxy, alkylthio, cyano or nitro; R 3 is hydrogen, alkyl, carboxy, protected carboxy, carbamoyl or tetrazol-5-yl; X is of formula --CH , --N or --C(COOR 6) , where R 6 is hydrogen or a carboxy-protecting group; Z is a single bond, alkylene or vinylene; and B is carboxy, protected carboxy or tetrazol-5-yl]; and pharmaceutically acceptable salts and esters thereof have the ability to inhibit the action of angiotensin II and thus can be used for the treatment and prophylaxis of hypertension and cardiac diseases.
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- Herbicidal benzoxazinone- and benzothiazinone-substituted pyrazoles
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The invention herein relates to titled compounds having the structure STR1 wherein the R1 -(R4)n members are as defined in the claims. Characteristic features of these compounds are the haloalkyl R2 radical and cyclization of two R4 members at the meta and para positions of the phenyl ring to form a substituted benzoxazinone ring fused to the phenyl or benzthiazinone ring. Such compounds are useful as active ingredients in herbicidal compositions to control undesirable weeds in various crops.
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- Kinetics of radical-initiated chain bromination of 2-methyl-2-propanol by N-bromosuccinimide in water
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The kinetics and product distribution of the radical chain bromination of 2-methyl-2-propanol (RH) by N-bromosuccinimide (SBr) in water have been studied by pulse-radiolytic and γ-radiolytic methods in order to obtain key data for the reactivity of the succinimidyl radical, S?. The products of the reaction after γ-radiolysis are dependent on the concentration of RH, being essentially made up of equal amounts of (CH3)2C(OH)CH2Br and succinimide at [RH] > 0.5 M, while the hydrolyzed ring-opened product, 3-bromopropionamide, increases at the expense of (CH3)2C(OH)CH2Br when the RH concentration is lowered. The chain-propagating steps R? + SBr → RBr + S? (i) and S? + RH → SH + R? (ii) of the S? mediated chain reaction had rate constants ki = (1.8 ± 0.3) × 108 (determined in three ways) and kii = (1 ± 0.5) × 107 M-1 s-1 (determined in four ways), respectively, whereas the corresponding rate constants for the Br? mediated chain under the same conditions were 2.5 × 109 and (5 ± 3) × 103 M-1 s-1. Under pulsed conditions with initial radical concentrations around 10-4 M, the chain length is ≈10. The ratio between kii and the rate constant for ring opening of S?, kiii (S? → ?CH2CH2CONCO), was determined to be 77 M-1, significantly higher than the corresponding value with neopentane as substrate and with dichloromethane as solvent (0.10 M-1). The kii value places S? as having significantly lower reactivity than OH? in hydrogen atom abstraction reactions, whereas a theoretical estimate based on electron affinities puts it in between Cl? and OH?, i.e. at higher reactivity than OH?. This provides kinetic evidence for the II nature of ground state S?. It was also established that Br? complexes rather strongly to SBr according to SBr + Br? → SBr2? (iv). As kiv = (4-7) × 103 M-1 and SBr2? is probably unreactive, the propagation rate of a bromine atom chain is expected to decrease with increasing SBr concentration.
- Lind, Johan,Jonsson, Mats,Xinhua, Shen,Eriksen, Trygve E.,Merényi, Gábor,Eberson, Lennart
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p. 3503 - 3510
(2007/10/02)
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- PHENYL HYDROXAMIC ACIDS INCLUDING A HETERO-CONTAINING SUBSTITUENT
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Phenyl hydroxamic acids are disclosed having the general formula or a pharmaceutically acceptable salt thereof, wherein X is NR, oxygen, sulfur, or a single bond, and Y is NR, oxygen, sulfur, or a single bond, where R can be hydrogen or lower alkyl, g can be 1 or 2, and with the proviso that at least one of X and Y is other than a single bond; Z is aryl, aralkyl or cycloalkyl; R1 is hydrogen, substituted or unsubstituted lower alkyl, cycloalkyl, lower alkenyl or aryl; R2 is hydrogen, lower alkyl, aroyl or acyl; m is 0 to 4 carbon atoms; and, n is 0 to 4 carbon atoms further providing that if one of X or Y is oxygen, the other of X or Y must be oxygen and further that when X and Y are oxygen Z cannot be aralalkyl. These new compounds have been found to be inhibitors or arachidonic acid 5-lipoxygenase and are therefore useful as antiallergy agents and antipsoriatics.
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- Long-chain α,ω-di-carboxylic acids and derivatives thereof and pharmaceutical compositions containing them
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A novel class of compounds has been found to be effective in blocking cholesterol and neutral lipid synthesis in-vivo without adversely affecting energy metabolism. The active compounds have the general formula STR1 or in-vivo hydrolysable functional derivatives of the carboxylic groups thereof, wherein R1 and R2 each independently represents an unsubstituted or substituted hydrocarbyl or heterocyclyl radical; X and Y each independently represent hydrogen, optionally substituted lower alkyl, halogen, cyano, carboxy, lower alkoxycarbonyl or carbamoyl; and Q represents a diradical consisting of a linear chain of 8 to 14 carbon atoms, one or more of which may be replaced by heteroatoms, said chain being optionally substituted by inert substituents and one or more of said carbon or heteroatom chain members optionally forming part of a ring structure. The invention also provides pharmaceutical compositions comprising the aforementioned compounds of formula (I) for the treatment of obesity, hyperlipidemia and maturity-onset diabetes.
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- Certain arylalkyl or pyridylalkyl hydroxamates useful for treating allergies and asthma
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Arylhydroxamates are provided having the structure STR1 wherein R1 is hydrogen, lower alkyl, aryl, lower alkenyl, cycloalkyl, or aralkyl; R2 is hydrogen, lower alkyl, aryl, cycloalkyl, alkanoyl or aroyl; m is 2 to 8; and STR2 wherein R3 is OH, COOH STR3 These compounds are useful as inhibitors of Δ5 -lipoxygenase and as such are useful as antiallergy agents.
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- Reactions of Benzotelluracyclopentane Diiodide
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Benzotelluracyclopentane diiodide (1) and the derivatives of the general formulate C8H8TeX2 (X=halide, pseudohalide, carboxylate) and +- (R=alkyl; X=halide) have been synthesized and characterized.I reacts with Na2S*9H2O to give C8H8Te which undergoes oxidative addition reactions yielding C8H8TeXY (XY=halogen, interhalogen, organic halide, N-bromosuccinimide or benzamide) and molecular adducts with HgCl2 and Cu2Cl2.Te-C (alkyl) and Te-N bonds are readily cleaved by electrophiles.The elemental analysis, molar conductance, uv, ir, pmr and tga data are presented in support of the structure of newly synthesized compounds.
- Srivastava, T. N.,Srivastava, P. C.,Kumar, Rakesh
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p. 186 - 190
(2007/10/02)
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- Photometric-Potentiometric Evaluation of the Hydrolysis Constants of N-Bromo Compounds
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The equilibrium concentrations of all reaction products emerging from the hydrolysis of N-bromo compounds in the presence of bromide and thereby also the hydrolysis constants (K1) have been calculated from the absorbance at 392.8 nm, the pH-value and the initial concentrations of the N-bromo compound and the bromide.The following compounds have been investigated: N-bromo-succinimide: K1 = 2.2E-6, 1,3-dibromo-5,5-dimethylhydantoin: K1 = 1.7E-5, N-bromoacetamide: K1 = 1.8E-6, N-bromo-monochloroacetamide: 5.2E-6, N-bromo-dichloroacetamide: K1 = 8.9E-6 and N-bromo-trichloroacetamide: K1 = 1.8E-5.The precision of the method, which is mainly suited for weak hydrolizing N-bromocompounds (K15-12percent.The reactivities in aqueous solution of the most frequently used N-bromo compounds are compared by means of the calculated HOBr equilibrium concentrations.The differences to be expected on the basis of the latters are at concentrations >1E-5 mol/l rather great, while they can be neglected in very dilute solutions (/=1E-6 mol/l).Keywords: Disinfection; Equilibrium concentrations; N-Halogene compounds; Hydrolysis; Reactivity of N-bromo compounds.
- Gottardi, Waldemar
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p. 313 - 322
(2007/10/02)
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- Benzoxazolyl-stilbenes
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Benzoxazolyl-stilbenes of the formula STR1 in which R is a 6-membered heterocyclic radical which has 2 nitrogen atoms in the o-position, m-position or p-position relative to one another, and one of Z and Zo is hydrogen and the other is hydrogen or chlorine, and the benzene nucleus A can carry conventional non-chromophoric substituents, processes for their preparation and their use for the fluorescent brightening of organic material.
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- Trifluoromethyl substituted 1-aminoindanes
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4(5 or 6 or 7)-Trifluoromethyl-1-aminoindanes, useful as inhibitors of N-methyl transferase.
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- Process for production of 6-aminopenicillanic acid or 7-aminocephalosporanic acid derivatives
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A derivative of 6-aminopenicillanic acid or 7-aminocephalosporanic acid is produced by a process which comprises chlorinating or brominating a 6-thioacylaminopenicillanic acid or 7-thioacylaminocephalosporanic acid compound to obtain a corresponding iminothiohalide compound, and then solvolyzing the iminothiohalide compound. The process is novel and industrially feasible for producing the amino compound, which is not accompanied by "reconversion reaction".
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