- A novel strategy for chromogenic chemosensors highly selective toward cyanide based on its reaction with 4-(2,4-dinitrobenzylideneamino)benzenes or 2,4-dinitrostilbenes
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N-(2,4-dinitrobenzylidene)-4-methoxyaniline (1), 4-(N,N-dimethylamine)-N-(2,4-dinitrobenzylidene) aniline (2), 2,4-dinitro-4′-methoxystilbene (3), and 2,4-dinitro-4′-(dimethylamino)stilbene (4) were synthesized and studied in dimethyl sulfoxide in a novel strategy as anionic chromogenic chemosensors. The color of the solutions of these compounds changed only in the presence of cyanide. The kinetic studies were performed with compounds 1-3 in an excess of cyanide. Higher second-order rate constant values were obtained for the compounds containing a methoxy group in relation to the compounds with a dimethylamino substituent, since the methoxy group donates electronic density to the 2,4-dinitrophenyl electron-accepting group less easily compared with the dimethylamino group. Stilbenes generally have greater structural rigidity than imines, facilitating the action of the substituents through the mesomeric effect. The data obtained indicate that the anion acts as a nucleophile, being responsible for C=N bond breaking. The C=C bridge is not broken in the stilbene dyes, but cyanide performs a nucleophilic attack on the 2,4-dinitrophenyl group.
- Heying, Renata S.,Nandi, Leandro G.,Bortoluzzi, Adailton J.,Machado, Vanderlei G.
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- Y-shape structured azo dyes with self-transforming feature to zwitterionic form as sensitizer for DSSC and DFT investigation of their photophysical and charge transfer properties
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Two novel azo dyes with D-π-A-π-D structures were designed and synthesized to investigate the relationship between molecular structure and sensitizing performance on applying for dye-sensitized solar cells (DSSCs) in comparison with their linear counterparts. Introducing hydroxyl auxiliary groups and arranging π-conjugation length as two parallel and series structural architectures, Y-shape and linear, led to red shift in absorption wavelength and increase in absorption intensity for the Y-shape pattern providing an efficient charge transfer pathway and improved Jsc and η of the DSSCs. Emerging a zwitterionic form, azonium structure, of the sensitizer in parallel configuration for the dyes 1a.p and 1b.p, enhanced light absorption domain and changed anchoring fashion could engendering improved electronic overlapping. The easily–synthesized dyes were evaluated for photophysical and electrochemical properties and turned out that the parallel-decorated dyes displayed better results than the series types as photosensitizers for DSSCs. ATR and Raman spectra clearly showed the adsorption of these dyes on the TiO2 surface. Operational tests of DSSCs, coated by titled azo dyes, illustrated that decorating π-conjugation pattern as parallel structure as well as accessorizing the donor unit with hydroxyl groups improved the photovoltaic performance. Optimized band gap due to participating the azonium structure and restricted electron recombination as well as rectified dye regeneration were proposed as main elements in enhancing performance parameters. A higher solar conversion efficiency was recorded for DSSCs based on the Y-shape dyes compared to other meta azo dye-based cells that were previously reported. Computational calculations were used to corroborate the opto-electrochemical traits of the dyes with a special concern on the influence of structural pattern on photovoltaic features.
- Alizadeh, Taher,Esrafili, Mehdi D.,Noruzi, Shima,Seyednoruziyan, Bahareh,Shamkhali, Amir Nasser,Zamanloo, Mohammad R.
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Read Online
- Preparation method of cationic blue dye
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The invention belongs to the technical field of dyes, and particularly relates to a preparation method of a cationic blue dye. According to the invention, a compound II is used as a diazonium component and a compound I is used as a coupling component for synthesizing the cationic blue dye for the first time; and the method has the advantages of simple process, environmental friendliness, high product purity, high yield and the like. The results of multiple production experiments with scales not below pilot tests show that mother liquor (such as mother liquor in steps 2, 3 and 4) in the reaction process can be cyclically used 6-8 times without treatment, so the amount of high-salt, high-COD and high-chroma wastewater is greatly reduced, a working environment is effectively improved while product yield is further increased and reaction reagent cost is saved, and the product still keeps high purity; and thus, product quality is guaranteed, production cost is reduced, and obvious economicbenefits, social benefits and environmental benefits are produced.
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Paragraph 0140-0142
(2020/02/14)
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- A Common, Facile and Eco-Friendly Method for the Reduction of Nitroarenes, Selective Reduction of Poly-Nitroarenes and Deoxygenation of N-Oxide Containing Heteroarenes Using Elemental Sulfur
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A transition metal-free, environment-friendly and practical protocol was developed either for the reduction of nitroarenes or for the deoxygenation of N-oxide containing heteroarenes. The reaction proceeded with the use of a non-toxic and cheap feedstock as elemental sulfur in aqueous methanol under relatively mild conditions. Green chemistry credentials were widely favorable compared to traditional and industrial protocols with good E-factors and a low production of waste. The strategy allowed the efficient reduction of a large variety of substituted-nitroarenes including various o-nitroanilines as well as selective reduction of various poly-nitroarenes in excellent yields with a broad substrate scope. The protocol was successfully extended to the deoxygenation of some N-oxide containing heteroarenes, like benzofuroxans, phenazine N,N'-dioxides, pyridine N-oxides, 2H-indazole N1-oxides, quinoxaline N1,N4-dioxides and benzo[d]imidazole N1,N3-dioxides. A gram-scale example for the synthesis of luminol, in green conditions, was reported. A solid mechanism of reaction was proposed from experimental evidences.
- Cerecetto, Hugo,Romero, Angel H.
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supporting information
(2020/03/23)
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- Azo aryl urea derivative, and preparation method and application thereof
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The invention relates to an azo aryl urea derivative, and a preparation and an application thereof, and concretely discloses a compound represented by formula (I), or an optical isomer, a cis-trans-isomer or a pharmaceutically acceptable salt thereof, and a preparation method thereof. Definitions of substituent groups in the general formula are described in the specification and claims. The invention further discloses a composition containing the above compound, and an application thereof. The compound has excellent anticancer activity on HepG2 liver cancer cells, MGC803 gastric cancer cells,HCT116 colon cancer and the like.
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Paragraph 0161-0162; 0163
(2020/06/17)
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- A preparation method of methylene blue
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The invention discloses a preparation method of methylene blue, and belongs to the technical field of intermediate synthesis in fine chemical engineering. The preparation method comprises the following steps: in a condensed hydrochloric acid solution, carrying out nitrosation reactions between sodium nitrite and N,N-dimethylaniline so as to obtain an intermediate namely p-nitroso-N,N-dimethylaniline; subjecting p-nitroso-N,N-dimethylaniline to hydrogenation reduction to prepare p-amino-N,N-dimethylaniline; oxidizing p-amino-N,N-dimethylaniline, then adding sodium thiosulfate to carry out addition reactions to prepare 2-amino-5-dimethylaminophenyl thiosulfonic acid, adding N,N-dimethylaniline into 2-amino-5-dimethylaminophenyl thiosulfonic acid to carry out oxidative condensation reactions to generate bis(4-dimethylaminophenyl) thiosulfonic acid; and making bis(4-dimethylaminophenyl) thiosulfonic acid carry out ring-closing reactions to obtain methylene blue. The provided preparation method has the advantages of high product purity, simple technology flow, low manufacture cost, suitability for industrial production, easily-available raw materials, and little pollution to the environment.
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Paragraph 0015; 0022; 0047; 0056; 0057; 0068; 0069; 0079
(2018/04/02)
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- METHODS OF CHEMICAL SYNTHESIS OF DIAMINOPHENOTHIAZINIUM COMPOUNDS INCLUDING METHYLTHIONINIUM CHLORIDE (MTC)
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Methods of synthesizing and purifying certain 3,7-diamino-phenothiazin-5-ium compounds (referred to herein as "diaminophenothiazinium compounds") including Methythioninium Chloride (MTC) (also known as Methylene Blue) are provided.
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Page/Page column 53; 56
(2015/04/28)
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- 4-N,N-Dimethylaminophenyl azide photooxidation: effect of conditions on the reaction pathway. Ring contraction of benzene to cyclopentadiene due to a strongly electron-donating substituent
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Abstract Depending on the reaction conditions employed, the photooxidation of 4-N,N-dimethylaminophenyl azide led to the formation of 4-N,N-dimethylaminonitrosobenzene and 4-N,N-dimethylaminonitrobenzene or (5Z)-2-(dimethylamino)-5-(hydroxyimino)cyclopenta-1,3-diene-1-carbaldehyde.
- Chainikova, Ekaterina,Khursan, Sergey,Lobov, Alexander,Erastov, Alexey,Khalilov, Leonard,Mescheryakova, Ekaterina,Safiullin, Rustam
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p. 4661 - 4665
(2015/08/06)
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- Synthesis of polyfunctional secondary amines by the addition of functionalized zinc reagents to nitrosoarenes
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Addition of functionalized aryl, heteroaryl or adamantyl zinc reagents to various nitroso-arenes in the presence of magnesium salts and LiCl in THF produces after a reductive work-up with FeCl2 and NaBH4 in ethanol the corresponding polyfunctional secondary amines in high yields. This journal is
- Dhayalan, Vasudevan,S?mann, Christoph,Knochel, Paul
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supporting information
p. 3239 - 3242
(2015/06/01)
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- NO2/H3BO3 as an effective nitrosonium source for electrophilic aromatic nitrosation under MW-promoted solvent-free conditions
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[Bmim]NO2/H3BO3 was used as a nitrosonium source for the efficient synthesis of nitrosoarenes. The reaction was accomplished under MW irradiation at 60 W in a solventless system. Side processes such as oxidation or dealkylation were not observed during the nitrosation of alkyl phenyl ethers in the presence of this new reagent. The satisfactory results were obtained with very short reaction time, simplicity in the experimental procedure and good to excellent yields.
- Valizadeh, Hassan,Gholipour, Hamid
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experimental part
p. 963 - 966
(2012/04/23)
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- New nitrite ionic liquid (IL-ONO) and nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica as nitrosonium sources for electrophilic aromatic nitrosation
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An improved method for the synthesis of nitrosoarenes has been developed using a new nitrite ionic liquid (IL-ONO) and immobilized nitrite ionic liquid. These ionic liquids play as nitrosonium sources for electrophilic aromatic nitrosation of active aromatics at 0-5 °C. Their action was accomplished in water and the satisfactory results were obtained under the mild conditions in short reaction time.
- Valizadeh, Hassan,Amiri, Mohammad,Shomali, Ashkan
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experimental part
p. 1103 - 1108
(2012/03/10)
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- A facile regioselective synthesis of (5-amino-4-cyano-1H-imidazol-1-yl) benzoic acids
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(Chemical Equation Presented) A simple and efficient method was developped for the synthesis of 3-(5-amino-4-cyano-1H-imidazol-1-yl)-4-substituted benzoic acids 3. These compounds were isolated by intramolecular cyclisation of the corresponding 3-{[(Z)-2-amino-1,2-dicyano-vinyl]amino}methyleneaminobenzoic acids in the presence of base.
- Barros, Siria A.,Goncalves, M. Sameiro T.,Oliveira-Campos, Ana M. F.,Proenca, Fernanda R. P.
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- Tin(IV) chloride-sodium nitrite as a new nitrosating agent for N-nitrosation of amines, amides and ureas under mild and heterogeneous conditions
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We have developed a new method of N-nitrosation of various secondary and tertiary amines, amides and ureas using a mixture of tin(IV) chloride and sodium nitrate. This method leads to a selective, high-yielding and mild heterogeneous N-nitrosation by in situ generation of nitrosyl chloride (NOCl). The reaction can be carried out in several different solvents such as chloroform, dichloromethane, ethers, ethyl acetate and alcohols, at room temperature. Georg Thieme Verlag Stuttgart.
- Celaries, Benoit,Parkanyi, Cyril
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p. 2371 - 2375
(2008/02/03)
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- METHODS OF CHEMICAL SYNTHESIS AND PURIFICATION OF DIAMINOPHENOTHIAZINIUM COMPOUNDS INCLUDING METHYLTHIONINIUM CHLORIDE (MTC)
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This invention pertains generally to the field of chemical synthesis and purification, and more specifically to methods of synthesizing and purifying certain 3,7 diamino-phenothiazin-5-ium compounds (referred to herein as "diaminophenothiazinium compounds") including Methythioninium Chloride (MTC) (also known as Methylene Blue). In one embodiment, the method comprises the steps of, in order: nitrosylation (NOS); nitrosyl reduction (NR); thiosulfonic acid formation (TSAF); oxidative coupling (OC); Cr(VI) reduction (CR); isolation and purification of zwitterionic intermediate (IAPOZI); ring closure (RC); chloride salt formation (CSF); one of: sulphide treatment (ST); dimethyldithiocarbamate treatment (DT); carbonate treatment (CT); ethylenediaminetetraacetic acid treatment (EDTAT); organic extraction (OE); and recrystallisation (RX). The present invention also pertains to the resulting (high purity) compounds, compositions comprising them (e.g., tablets, capsules), and their use in methods of inactivating pathogens, and methods of medical treatment and diagnosis, etc., for example, for tauopathies, Alzheimer's disease (AD), skin cancer, melanoma, viral diseases, bacterial diseases, or protozoal diseases.
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Page/Page column 67-74
(2010/10/20)
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- Nitrosation of arenes with nitrosonium ethyl sulfate
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Nitrosonium ethyl sulfate reacts with O-alkylphenols and N,N-dialkylanilines to give the corresponding 4-nitrosoarenes. The reaction is not accompanied by side processes characteristic of common nitrosating agents. Diazotization of primary aromatic amines with nitrosonium ethyl sulfate yields stable diazonium salts, which are promising reagents for organic synthesis.
- Zyk,Nesterov,Khlobystov,Zefirov
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p. 506 - 509
(2007/10/03)
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- Nitroso Compounds by Reaction of Organomercurials with Nitrosyl Chloride
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By the reaction of RHgX (X = Cl, Br, OAc) with NOCl, mercury is eliminated as ClHgX and, if R is aromatic, nitroso compounds are obtained, i.e., nitrosobenzene, 1-nitrosonaphthalene, 4-nitroso-N,N-dimethylaniline, 2-nitrosophenol, 4-nitrosophenol and methyl 3-nitrososalicylate. If R is aliphatic or alicyclic, with RHgX to NOCl 1:3, gem-chloronitroso compounds are obtained that have not been described previously, i.e., 2-chloro-2-nitrosocyclohexanol, 1-acetoxy-2-chloro-2-nitrosocyclohexane, 1-chloro-2-methoxy-1-nitrosocyclopentane, methyl 2-chloro-2-nitroso-3-methoxypropionate, 1-chloro-1-nitroso-ethane and 2-chloro-2-nitrosoethanol. All products have been characterized by chemical and IR spectral analysis.
- Grdenic, Drago,Vrdoljak, Visnja,Korpar-Colig, Branka
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p. 1361 - 1366
(2007/10/03)
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- SYNTHETIC METHODS. PART 23. REARRANGEMENT OF SOME HYDROXAMIC ACIDS INTO AMIDES. A SELF-CONDENSATION LEADING TO DISPROPORTIONATION
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Pyruvic acids have been shown to react with p-nitroso-N,N-dimethylaniline (1) to produce p-dimethyl-aminoacetanilides (3) via the corresponding hydroxamic acids (4).Three such intermediates (4a, c, d) have been isolated and their structure proved by n.m.r. and mass spectroscopy and elemental analysis.Solutions of the hydroxamic acids (4) have been shown to undergo concentration-dependent self-condensation and disproportionation leading to the amides (3) and acids (5).Rational pathways for these transformations are discussed.Spectral correlations permit differentiation between the amides (3) and the corresponding hydroxamic acids (4).
- Hassner, Alfred,Ruse, Margareta,Gottlieb, Hugo E.,Cojocaru, Miriam
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p. 733 - 738
(2007/10/02)
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- The Photochemistry of Some Methoxy and Dimethylamino Derivatives of Azoxybenzene
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The photochemistry of the six azoxybenzene derivatives carrying a methoxy and/or a dimethylamino group in positions 4/4' has been examined in alcogols and in benzene and found to lead to different processes.The photo-Wallach rearrangement takes place for all except the disubstituted derivatives.This process involves an intermediate, which either gives back the starting azoxy or is converted to the final o-hydroxy derivative through acid catalysis as well as by the previously reported basic catalysis or via cleavage to diazonium ions, which can be trapped before recombination.Oxygen shift to yield the isomeric azoxy derivative (only one precedent known) is a general, one-way process, leading in every case to the azoxy benzene with the N->O group far from the ring carrying the stronger electron-donating substituent.Differently from the photo-Wallach rearrangement, this process shows little solvent dependence.The dimethylamino derivatives undergo also or exclusively different fragmentations, such as intramolecular hydrogen abstraction and cleavage of either the N=N or the C-N bond.The solvent and substituent effect upon electronic spectra, reaction quantum yield, and product distribution are discussed.The photochemistry is attributed to a ?,?* state with strong internal charge transfer.
- Albini, Angelo,Fasani, Elisa,Moroni, Micaela,Pietra, Silvio
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- Nitrosation process
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In the process of subjecting a compound selected from phenols, N,N-dialkylanilines and mixtures thereof to nitrosation reaction conditions using a nitrite in an aqueous system to prepare nitrosated products selected from benzoquinone oximes and p-nitroso-N,N-dialkylanilines, the nitrosation reaction is advantageously carried out in the presence of an acid stronger than nitrous acid an organic acid of pKa 2 to pKa 5 or a salt thereof and water, the quantities of the organic acid and water being up to 5 times by mole and up to 10 times by weight the quantity of the compound to be nitrosated, respectively.
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