- Synthesis, characterization, and heterobimetallic cooperation in a titanium-chromium catalyst for highly branched polyethylenes
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A heterobimetallic catalyst, {Ti - Cr}, consisting of a constrained-geometry titanium olefin polymerization center (CGCEtTi) covalently linked to a chromium bis(thioether)amine ethylene trimerization center (SNSCr) was synthesized and fully characterized. In ethylene homopolymerizations it affords linear low-density polyethylene with molecular weights as high as 460 kg·mol-1 and exclusively n-butyl branches in conversion-insensitive densities of ～18 branches/1000 carbon atoms, which are ～17 and ～3 times (conversion-dependent), respectively, those achieved by tandem mononuclear CGCEtTi and SNSCr catalysts under identical reaction conditions.
- Liu, Shaofeng,Motta, Alessandro,Delferro, Massimiliano,Marks, Tobin J.
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- Nanosized inorganic metal oxides as heterogeneous catalysts for the degradation of chemical warfare agents
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Nanosized inorganic metal oxides, such as TiO2, ZnO, γ-Al2O3, are proposed as heterogeneous catalysts for the oxidative degradation of chemical warfare agents (CWA), particularly of organosulfur toxic agents, into oxidised products with reduced toxicity. The morphology, structural and textural properties of the catalysts were investigated. Furthermore, their catalytic properties were evaluated in the oxidative abatement of (2-chloroethyl)ethylsulfide, CEES, a simulant of sulfur mustard (blistering CWA). Their performance was also compared to a conventional decontamination powder and a commercial Nb2O5 sample. The metal oxides powders were then employed in the active oxidative decontamination of CEES from a cotton textile substrate, mimicking a real contamination occurrence. Remarkable results in terms of abatement and degradation into desired products were recorded, achieving good conversions and decontamination efficiency with Nb2O5, TiO2 and γ-Al2O3, under very mild conditions, with hydrogen peroxide (as aqueous solution or as urea-hydrogen peroxide adduct), at room temperature and ambient pressure. In the aim of a real on-field use, the potential environmental impact of these solids was also evaluated by bioluminescence toxicity tests on reference bacteria (Photobacterium leiognathi Sh1), showing a negligible negative impact for TiO2, γ-Al2O3, and Nb2O5. A major biotoxic effect was only found for ZnO.
- Bisio, Chiara,Carniato, Fabio,Palumbo, Chiara,Safronyuk, Sergey L.,Starodub, Mykola F.,Katsev, Andrew M.,Marchese, Leonardo,Guidotti, Matteo
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- Decontamination of 2-chloro ethyl ethyl sulphide and dimethyl methyl phosphonate from aqueous solutions using manganese oxide nanostructures
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Current study investigates the efficiency of reactive adsorbent composed of MnO2 nanoparticles and nanorods for the detoxification of 2-chloro ethyl ethyl sulphide (CEES) and dimethyl methyl phosphonate (DMMP), well-known simulants of sulphur mustard and sarin, respectively. The MnO2 nanoparticles and nanorods were synthesised using novel reactive magnetron sputtering technique and then characterised by powder XRD, Raman spectroscopy, FE-SEM, TEM, BET, FT-IR and Thermogravimetry (TG) analysis. Powder XRD and Raman results confirm the formation of pure tetragonal phase of MnO2 nanostructure material. The FE-SEM and TEM analysis exhibited the formation of aggregate MnO2 nanoparticles and nanorods. The surface area of the synthesised aggregate MnO2 nanoparticles and nanorods (164.28 m2/g) was found to be enhanced significantly in comparison with what was reported in the literature. Decontamination reactions of synthesised nanostructure material were examined by GC equipped with FID and the products obtained after reaction were analysed by GC-MS and FT-IR techniques. It was observed that the currently synthesised MnO2 nanoparticles and nanorods exhibit much better decontamination results towards CEES as well as DMMP in comparison to or as per existing solid decontaminants. The reactions exhibited pseudo first order kinetic behaviour with rate constant and half life value 0.267 h- 1 and 2.58 h for CEES and 0.068 h- 1 and 10.10 h for DMMP, respectively. The data exhibits the formation of non-toxic hydrolysis products in the detoxification of CEES as well as DMMP.
- Verma, Monu,Chandra, Ramesh,Gupta, Vinod Kumar
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- Hydrolysis of Mustard Derivatives in Aqueous Acetone-Water and Ethanol-Water Mixtures
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The hydrolyses of two mustard derivatives, 2-chloroethyl ethyl sulfide (CEES) and 2-chloroethyl methyl sulfide (CEMS), were investigated and compared with the hydrolysis of tert-butyl chloride (TBC) in aqueous binary mixtures of acetone and ethanol from 0 to 45 deg C.The solvent effect on rates and on activation parameters provided further evidence for an SN1 mechanism with anchimeric assistance of the sulfur atom to form a cyclic sulfonium ion as the reaction intermediate.Lower ΔH(excit.) and ΔS(excit.) values of both CEES and CEMS relative to that of TBC reflected the S-C bond formation and the strained structure of the intermediate.A finite and negative ΔCp(excit.) was detected.The observed ΔH(excit.) was corrected for the cosolvent effect by adopting Fagley's model and was consistent with the value in pure water.
- Yang, Yu-Chu,Ward, J. Richard,Luteran, Thomas
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- Effect of crystallographic structure of MnO2 on degradation of 2-CEES
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In this study, four MnO2 samples with different crystallographic structures (α-, β-, δ- and γ-MnO2) were synthesized by the hydrothermal method. The relationship between the characteristics of the four crystalline samples and their degradation ability against 2-chloroethyl ethyl sulfide (2-CEES), a simulant of the chemical warfare agent sulfur mustard, and the relevant reaction mechanism were investigated. Characterization data indicated that the various crystal types displayed different specific surface areas, frequency of lattice defects, amounts of adsorbed/inserted water, and numbers and strength of basic sites. The combined effects of these differences caused different degradation activity in 2-CEES degradation to be observed. The reaction followed pseudo-first-order kinetics, whereby γ-MnO2 exhibited the highest degradation activity. The mechanism of 2-CEES degradation was studied by gas chromatography and infrared spectroscopy methods, and data indicated the key role played by substrate hydrolysis and oxidation in the degradation process.
- Guo, Yueting,Kong, Lingce,Lei, Meiling,Xin, Yi,Zuo, Yanjun,Chen, Wenming
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- A New Hexa-TiIV-Substituted Sandwich-Type Polyoxotungstate: Hydrothermal Synthesis, Structure, and Oxidative Decontamination of Chemical Warfare Agent Simulant
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A new hexa-TiIV-substituted sandwich-type silicotungstate, Na2(H2enMe)4[Ti6(μ-O)9(A-α-SiW9O34H2)2]·16H2O (1, enMe = 1,2-diaminopropane) has been synthesized under mild hydrothermal conditions and characterized by FT-IR spectroscopy, elemental analysis, thermogravimetric analysis, single-crystal and powder X-ray diffraction. Compound 1 contains a dimeric polyoxoanion with two [A-α-SiW9O34]10– Keggin moieties sandwiching a trigonal-prismatic [Ti6(μ-O9)]6+ cluster. The catalytic performance of 1 was evaluated for the oxidative decontamination of chemical warfare agent, i.e. sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), using H2O2 under ambient conditions, showing that 1 is an excellent catalyst for the rapid and complete transformation from CEES to nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) with 100 % selectivity. In addition, 1 exhibits good stability and recyclability.
- Qin, Dan,Sun, Jun-Jun,Wang, Yue-Lin,Yang, Guo-Yu
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- Preparation of a porphyrin-polyoxometalate hybrid and its photocatalytic degradation performance for mustard gas simulant 2-chloroethyl ethyl sulfide
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By combining 5,10,15,20-tetra(4-chlorine)phenylporphyrin (TClPP) and α-Keggin polyoxometalate H5PV2Mo10O40 (H5PVMo) via a simple ion-exchange method, an organic-inorganic hybrid material [C44H28N4Cl4]1.5[H2PMo10V2O40]·2C2H6O (H2TClPP-H2PVMo) was prepared and thoroughly characterized by a variety of techniques. The homogeneous photocatalytic degradation of 2-chloroethyl ethyl sulfide (CEES) (5 μL) by H2TClPP-H2PVMo (1 × 10?6 mol/L) was studied in methanol and methanol-water mixed solvent (v/v = 1:1), in which the degradation rate of CEES reached 99.52% and 99.14%, respectively. The reaction followed first-order reaction kinetics, and the half-life and kinetic constant in methanol and the mixed solvent were respectively 33.0 min, ?0.021 min?1 and 15.7 min, ?0.043 min?1. Mechanism analysis indicated that under visible light irradiation in the air, CEES was degraded via oxidation and alcoholysis/hydrolysis in methanol and the mixed solvent. O2·? and 1O2 generated by H2TClPP-H2PVMo selectively oxidized CEES into a nontoxic sulfoxide. Singlet oxygen capture experiments showed that H2TClPP-H2PVMo (? = 0.73) had a higher quantum yield of singlet oxygen than TClPP (? = 0.35) under an air atmosphere and visible light irradiation.
- Tao, Fangsheng,Tian, Shubo,Wang, Yong'an,Yang, Ying,Zhang, Lijuan,Zhong, Yuxu,Zhou, Yunshan
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supporting information
(2022/01/03)
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- A dual-function all-inorganic intercluster salt comprising the polycation ?-[Al13O4(OH)24(H2O)12]7+and polyanion α-[PMo10V2O40]5-for detoxifying sulfur mustard and soman
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?-[Al13O4(OH)24(H2O)12]7+, which shares similarity with the phosphotriesterase active site ZnII-OH-ZnII, was specially chosen to interact with the cluster α-PMo10V2O405- to form a new three-dimensional intercluster, which crystallized in the monoclinic space group P21/m with Z = 2, for the decontamination of chemical warfare agents. The experimental results showed that 50 mg of the compound decontaminated 96.4percent (within 120 min) and 99.5percent (within 40 min) of sulfur mustard (HD) (4 μL) and soman (GD) (4 μL), respectively, in ambient conditions. The decontamination processes followed first-order reaction kinetics with a rate constant and half-life of 0.01234 min-1 and 56.15 min for HD and 0.1198 min-1 and 5.78 min for GD, respectively. It was concluded that the α-PMo10V2O405- moiety was responsible for the catalytic oxidation of HD into non-toxic sulfoxide, while the ?-[Al13O4(OH)24(H2O)12]7+ moiety was responsible for the catalytic hydrolysis of HD and GD into nontoxic hydrolysates. Besides, the compound showed notable efficacy for the decontamination of HD on guinea pig skin and of GD on Kunming mouse skin, indicating high potential for use in human skin protection and treatment. This journal is
- Gao, Qi,Tao, Fangsheng,Wang, Yong'An,Yin, Jianbo,Yu, Jialin,Zhang, Lijuan,Zhong, Yuxu,Zhou, Yuanyuan,Zhou, Yunshan
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p. 8122 - 8135
(2020/07/10)
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- (POLY)THIOL COMPOUND PRODUCTION METHOD
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PROBLEM TO BE SOLVED: To provide a production method capable of realizing a (poly)thiol compound of interest with high yields efficiently and inexpensively in a simple manner. SOLUTION: The (poly)thiol compound production method comprises reacting hydrogen sulfide with an organic halogen compound represented by the general formula (1) defined by Q1-(X)n in the presence of one or more base compounds having a pKa from 4 to 13 inclusive, thereby producing a (poly)thiol compound represented by the general formula (2) defined by Q2-(SH)n. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0085; 0088-0093; 0096-0104; 0107-0108
(2019/12/15)
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- Textile/metal-organic-framework composites as self-detoxifying filters for chemical-warfare agents
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Abstract The current technology of air-filtration materials for protection against highly toxic chemicals, that is, chemical-warfare agents, is mainly based on the broad and effective adsorptive properties of hydrophobic activated carbons. However, adsorption does not prevent these materials from behaving as secondary emitters once they are contaminated. Thus, the development of efficient self-cleaning filters is of high interest. Herein, we report how we can take advantage of the improved phosphotriesterase catalytic activity of lithium alkoxide doped zirconium(IV) metal-organic framework (MOF) materials to develop advanced self-detoxifying adsorbents of chemical-warfare agents containing hydrolysable P-F, P-O, and C-Cl bonds. Moreover, we also show that it is possible to integrate these materials onto textiles, thereby combining air-permeation properties of the textiles with the self-detoxifying properties of the MOF material. The silk of human kindness: Insertion of lithium alkoxides in zirconium metal-organic frameworks (MOF) which are then deposited on silk fibers gives rise to protective fabrics capable of self-detoxifying chemical-warfare agents. The fabrics combine the air-permeation properties of the textiles with the highly active phosphotriesterase catalytic activity of the MOF for the hydrolysis of P-F, P-O, and C-Cl bonds.
- L?pez-Maya, Elena,Montoro, Carmen,Rodríguez-Albelo, L. Marleny,Aznar Cervantes, Salvador D.,Lozano-Pérez, A. Abel,Cenís, José Luis,Barea, Elisa,Navarro, Jorge A. R.
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supporting information
p. 6790 - 6794
(2015/06/08)
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- Mechanistic insights into the hydrolysis of 2-chloroethyl ethyl sulfide: The expanded roles of sulfonium salts
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The hydrolysis of 2-chloroethyl ethyl sulfide has been examined in an effort to better understand its mechanism under more concentrated conditions. Two salts formed during hydrolysis were synthesized, and an emphasis was placed on determining their effect on the reaction as it proceeded. Unexpected changes in mechanism were seen when excess chloride was added to the reaction. By measuring rates and product distributions as the products were added back into the hydrolysis, a mechanism was developed. The formation of these sulfonium salts represents additional products in the disappearance of 2-chloroethyl ethyl sulfide with k3 in particular causing a deviation away from expected first-order behavior. Sulfonium salts 3 and 4 do not appear to interconvert, and the system as a whole had fewer pathways available than previously proposed. Initial conditions for studying the hydrolysis were very important and could lead to different conclusions depending on the conditions used. This work will aid in better understanding the hydrolysis of the very toxic chemical warfare agent mustard (bis(2-chloroethyl)sulfide) in the environment and during its decontamination.
- Bae, Su Y.,Winemiller, Mark D.
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p. 6457 - 6470
(2013/07/26)
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- Elongated titanate nanostructures and their applications
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Recent advances in the synthesis, characterisation and applications of elongated titanate and TiO2 nanostructures (including nanotubes, nanofibres and nanorods) are reviewed. The physicochemical properties of nanostructures, such as high surface area, efficient ion-exchange properties, electron and proton conductivity and high aspect ratio, are described in connection with a particular application. Practical aspects of the preparation, stability and transformation of elongated titanates are considered. A critical survey of the literature is provided together with the development of prospective energy applications of elongated titanates in catalysis, photo-catalysis, electrocatalysis, solar cells, fuel cells, lithium batteries and hydrogen storage. Other applications utilising the high aspect ratio of elongated nanostructures include biomedical implants, sensors, drug delivery systems and smart, tribological composite coatings. Wiley-VCH Verlag GmbH & Co. KGaA.
- Bavykin, Dmitry V.,Walsh, Frank C.
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scheme or table
p. 977 - 997
(2009/06/17)
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- Locus-specific microemulsion catalysts for sulfur mustard (HD) chemical warfare agent decontamination
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The rates of catalytic oxidative decontamination of the chemical warfare agent (CWA) sulfur mustard (HD, bis(2-chlororethyl) sulfide) and a range (chloroethyl) sulfide simulants of variable lipophilicity have been examined using a hydrogen peroxide-based microemulsion system. SANS (small-angle neutron scattering), SAXS (small-angle X-ray scattering), PGSE-NMR (pulsed-gradient spin-echo NMR), fluorescence quenching, and electrospray mass spectroscopy (ESI-MS) were implemented to examine the distribution of HD, its simulants, and their oxidation/hydrolysis products in a model oil-in-water microemulsion. These measurements not only present a means of interpreting decontamination rates but also a rationale for the design of oxidation catalysts for these toxic materials. Here we show that by localizing manganese-Schiff base catalysts at the oil droplet-water interface or within the droplet core, a range of (chloroethyl) sulfides, including HD, spanning some 7 orders of octanol-water partition coefficient (Kow), may be oxidized with equal efficacy using dilute (5 wt. % of aqueous phase) hydrogen peroxide as a noncorrosive, environmentally benign oxidant (e.g., t1/2 (HD) ～ 18 s, (2-chloroethyl phenyl sulfide, C6H5SCH2CH 2Cl) ～ 15 s, (thiodiglycol, S(CH2CH 2OH)2) ～ 19 s {20°C}). Our observations demonstrate that by programming catalyst lipophilicity to colocalize catalyst and substrate, the inherent compartmentalization of the microemulsion can be exploited to achieve enhanced rates of reaction or to exert control over product selectivity. A combination of SANS, ESI-MS and fluorescence quenching measurements indicate that the enhanced catalytic activity is due to the locus of the catalyst and not a result of partial hydrolysis of the substrate.
- Fallis, Ian A.,Griffiths, Peter C.,Cosgrove, Terence,Dreiss, Cecile A.,Govan, Norman,Heenan, Richard K.,Holden, Ian,Jenkins, Robert L.,Mitchell, Stephen J.,Notman, Stuart,Platts, Jamie A.,Riches, James,Tatchell, Thomas
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supporting information; scheme or table
p. 9746 - 9755
(2011/03/20)
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- Reaction of thiometon and disulfoton with reduced sulfur species in simulated natural environment
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The reactions of thiometon and its ethyl analogue, disulfoton, with reduced sulfur species [e.g., bisulfide (HS-), polysulfide (S n2-), thiophenolate (PhS-), and thiosulfate (S2O32-)] were examined in well-defined aqueous solutions under anoxic conditions. The role of reduced sulfur species was investigated in the abiotic degradation of thiometon and disulfoton. Experiments at 25°C demonstrated that HS-, Sn2-, PhS-, and S2O32- promoted the degradation of thiometon to a great extent while only Sn2- and PhS- showed a small accelerating effect in the degradation of disulfoton. Reactions were monitored at varying concentrations of reduced sulfur species to obtain the second-order rate constants. The reactivity of the reduced sulfur species decreased in the following order: Sn 2- > PhS- > HS- ≈ S2O 32-. Transformation products were confirmed by standards or characterized by gas chromatography mass spectrometry. The results illustrate that multiple pathways occur in the reactions with reduced sulfur species, among which the nucleophilic attack at the α-carbon of the alkoxy group was the predominant pathway. Activation parameters of the reaction of thiometon and disulfoton with HS- were also determined from the measured second-order rate constants over a temperature range. ΔH≠ values indicated that the reactivity of thiometon toward HS- was much greater than for disulfoton. Nucleophilic attack at the alkoxy group was more important for thiometon than disulfoton. When the measured second-order rate constants at 25°C are multiplied by [HS-] and ∑[S n2-] reported in saltmarsh porewaters, predicted half-lives show that reduced sulfur species present at environmentally relevant concentrations may present an important sink for thiometon in coastal marine environments.
- Gan, Qui,Jans, Urs
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p. 7753 - 7760
(2007/10/03)
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- Rhenium catalyzed sulfoxide reduction
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A mild, efficient method for the catalytic reduction of sulfoxides to sulfides with triphenylphosphine and the catalyst ReOCl3(PPh3)2 (I) is reported. Aryl sulfoxides are reduced faster than alkyl, and the reaction is successful for sterically hindered sulfoxides and those with common organic functional groups.
- Arterburn, Jeffrey B.,Perry, Marc C.
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p. 7941 - 7944
(2007/10/03)
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- NEW ROUTE TO THE PREPARATION OF 1,3,2 OXATHIAPHOSPHOLANES 2-SULFIDE DERIVATIVES
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5-Substituted 2-alkyl (or aryl, heteroaryl,...)thio 1,3,2 oxathiaphospholanes 2-sulfide 5 are readily accessible by reaction of the triethylammonium salt 1 of a diester of the phosphorotetrathioic acid with appropriate epoxide in the presence of BF3*Et2O as catalyst.
- Comel, Alain,Kirsch, Gilbert,Paquer, Daniel
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- SYNTHESIS OF 1,3,2-OXATHIAPHOSPHOLANE-2-SULFIDE DERIVATIVES
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5-Substituted 2-alkyl (or aryl, heteroaryl, ...)thio-1,3,2-oxathiaphospholane-2-sulfides 5 are readily accessible by reaction of the triethylammonium salt 1 of a diester of the phosphorotetrathioic acid with appropriate epoxides in the presence of BF3/Et2O as catalyst.Key words: BF3/Et2O; cyclisation reaction; NMR; oxathiaphospholane derivatives; oxiranes; phosphorotetrathioic acid; triethylammonium salts.
- Comel, Alain,Kirsch, Gilbert,Paquer, Daniel
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p. 229 - 234
(2007/10/02)
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- THE CHARACTERIZATION OF SULFONIUM CHLORIDES BY GAS CHROMATOGRAPHY/MASS SPCTROMETRY AND THE DEGRADATION OF 2-CHLOROETHYL SULFIDE DERIVATIVES
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Three aqueous samples containing sulfonium chloride salts of both mustard gas (2,2'-dichlorodiethylsulfide) and its simulant 2-chloroethyl ethyl sulfide have been characterized by gas chromatography/mass spectrometry (GC/MS).Theese salts decompose thermallly to the sorresponding 2-chloroethyl and 2-hydroxyethyl sulfides, therefore GC/MS analysis is not indicative of the true composition of these solutions.Small amounts of dithioethers characteristic of the decomposition of the dimeric salts were also detected.Electron Impact (EI) ionization produces a more intense molecular ion than methane chemical ionization (CI) for the dithioethers because of the ease of formation of sulfonium ions during chemical ionization.The composition products of four aged samples of 2-chloroethyl sulfides (RSCH2CH2Cl where R=methyl, ethyl, phenyl and benzyl groups) were also characterized by GC/MS, which indicated that decomposition of these compounds may proceed via dimeric sulfonium ions.Mustard gas was detected in all but one of the samples, providing evidence for secondary sulfonium cation formation in the degradation prcess.Keywords: Sulfonium chlorides; 2-chloroethyl sulfides; degradation; dimeric sulfonium cations; GC/MS characterization.
- Rourhbaugh, Dennis K.,Yang, Yu-Chu,Ward, J. Richard
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- Kinetics and Mechanism of the Hydrolysis of 2-Chloroethyl Sulfides
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The hydrolysis of 2-chloroethyl sulfides approaches an SN1 mechanism only under limiting conditions where the substrate is predissolved in an organic solvent prior to addition to water and the concentration is kept below 0.001 M.At greater substrate concentrations the kinetics are complicated by the formation of dimeric sulfonium chloride salts.These salts are formed in pure water, in buffered aqueous solution at pH 10, and in binary acetone-water solutions.The sulfonium chlorides are relatively stable and decompose via an SN2 mechanism.One pathway includes the reversible formation of the initial sulfide substrate.This reaction presumably accounts for the recurring toxicity of mustard (2,2'-dichlorodiethyl sulfide) in human and natural environment.The presence of a powerful nucleophile such as thiosulfate can effectively capture the transient ethylenesulfonium ion intermediate formed during the initial step of hydrolysis.All dimeric sulfonium chloride salts are eliminated from the solution in the presence of thiosulfate anion, and the observed rate of displacement reaction at 0.1-O.2 M substrate is equivalent to that measured for the limiting SN1 mechanism at a substrate concentration below 0.001 M.
- Yang, Yu-Chu,Szafraniec, Linda L.,Beaudry, William T.,Ward, J. Richard
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p. 3293 - 3297
(2007/10/02)
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- THE CHEMISTRY OF α,ω-MERCAPTOALCOHOLS IN THE PRESENCE OF DIETHOXYTRIPHENYLPHOSPHORANE. TEMEPERATURE DEPENDENCE OF CYCLODEHYDRATIONS AND S-ETHYLATIONS
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Diethoxytriphenylphosphorane (DTPP) is easily prepared by oxidative addition of triphenylphosphine with diethyl peroxide.DTPP converts a variety of mercaptoalcohols to cyclic sulfides as well as hydroxythioethers.The temperature dependence (+25 --> -25 deg C) of the product distribution has synthetic petential.
- Robinson, Philip L.,Kelly, Jeffery W.,Slayton, A. Evans
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- DIOXYPHOSPHORANES, AN EMERGING CLASS OF VERSATILE REAGENTS FOR ORGANIC SYNTHESIS
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Several ?-dioxyphosphoranes have been prepared and their structural characterizations using NMR techniques support the trigonal bipyramidal conformer as the most stable for the acyclic phosphoranes.Their utility in smooth conversions of hydroxylated substrates to the corresponding X-heterocycles is documented.
- Kelly, Jeffery W.,Robinson, Philip L.,Evans, Slayton A.
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p. 147 - 150
(2007/10/02)
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- Process for the industrial preparation of water insoluble azo dyestuffs containing cyano groups from the corresponding halogen compounds
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A process for the manufacture of a cyano azo dyestuff insoluble in water, of the formula (I) from a halogenated azo compound of the formula (II) in which A denotes a benzene radical carrying one or more nitrile or halogen substituents in the ortho position with respect to the azo group, Hal represents a halogen atom, in particular bromine, chlorine or iodine, B denotes the radical of a coupling component, preferably a substituted para-amino arylene radical, A and B are free from water-solubilizing groups and may carry other substituents usual in azo dyestuffs, n is 1 or 2, characterized in that a compound of formula (II) is reacted with an alkali metal cyanide, preferably sodium cyanide, and the operation is effected in the absence of water and in a solvent formed by a thioether of the formula (III) where R and R' are the same or different and denote an alkylene radical having from 1 to 8 carbon atoms, a straight or branched chain able to contain an --O-- or --S-- bridge and in the presence of a catalyst constituted by a combination between the thioether of formula (III) and a cuprous salt.
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