- A comprehensive spectroscopic, solvatochromic and photochemical analysis of 5-hydroxyquinoline and 8-hydroxyquinoline mono-azo dyes
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A series of novel substituted-azo dyes 8-(aryldiazenyl)quinolin-5-ol (5a-i) were synthesized by the coupling reaction of 5-hydroxyquinoline with diazotized aniline derivatives in the presence of NaNO2 in HCl/H2O mixture. The study of
- Coelho, Paulo J.,Lup, Andrew Ng Kay,Mahon, Peter J.,Pesyan, Nader Noroozi,Ramezanitaghartapeh, Mohammad,Raposo, M. Manuela M.,Rashidnejad, Hamid,Soltani, Alireza
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- Preparation method of 3-[3-(-benzotriazole -2-base)-4-hydroxy -5-tert-butylphenyl]- propionate (by machine translation)
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3 - (3,5 - Of the process reduces, the tedious degree) of the process, omits the crystallization separation process, in the preparation process of the target product, saves the raw material ", and reduces the output " of waste, water and inorganic salt and other wastes 3 - [3 - (.) - 4 - The method, of the, present invention reduces the complexity, of the process by the. method] - of separating, and purifying the intermediate product, without isolation. (by machine translation)
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Paragraph 0052-0053
(2020/05/08)
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- Preparing method of ultraviolet absorber UV-234
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The invention provides a preparing method of an ultraviolet absorber UV-234. The preparing method comprises the steps of conducting ammoniation, diazotization, coupling, first-step reduction, second-step reduction reaction and post-treatment on ortho-nitrochlorobenzene to prepare 2-[2'-hydroxy-3',5'-di(alpha,alpha-dimethyl benzyl)phenyl]benzotriazole. According to the preparing method, ortho-nitrochlorobenzene is ammonified by adopting ammonium hydroxide with the concentration of 10-25%, then is subjected to diazotization with nitrite to produce diazonium salt, no diazotization needs to occurunder a strong acid medium, by-product ammonium hydroxide of existing products of a company is comprehensively utilized, low emission of three wastes is achieved, and the required cost is low; a two-step reduction method is adopted in a reduction ring closing process of intermediate azo products, the situation is avoided that a strong reduction agent directly reduces azo double bonds into amine, impurity production is reduced, and not only is the purity of the products increased but also the product yield is increased.
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- Preparation method of ultraviolet absorbent UV - 329 (by machine translation)
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The invention provides a preparation method, UV - 329, of an ultraviolet absorber. The method comprises the following steps: performing ammonification, diazotization, coupling, one-step reduction, two-step reduction reaction and post-treatment to prepare 2 - (2 '- hydroxyl -5' - t-octylphenyl) benzotriazole product by o-nitrochlorobenzene. To the method, by ammonia water with a concentration 10%~25%, o-nitrochlorobenzene is subjected to diazotization reaction with nitrite to generate a diazonium salt, the diazotization reaction does not need to be carried out in a strong acid medium, and byproduct ammonia water of the product in the company is comprehensively utilized. The reduction closed-loop process of the intermediate azo product adopts 2-step reduction method, the strong reducing agent is prevented from directly reducing the azo double bond to the amine, impurity generation, product purity, and yield. (by machine translation)
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- OPTICAL MATERIAL COMPRISING A RED-SHIFTED BENZOTRIAZOLE UV ABSORBER
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The present invention relates to an eyeglass lens comprising a substrate made of an optical material comprising a polymer matrix and at least one 2-(2-hydroxy-5-R1-phenyl)benzotriazole, in which R1 is a resonant group, the optical tr
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Paragraph 0103; 0104
(2019/04/26)
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- New fluorescent symmetrically substituted perylene-3,4,9,10-dianhydride- azohybrid dyes: Synthesis and spectroscopic studies
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Five phenolic azo-dyes (3a-e) were synthesized by diazo coupling of the suitably substituted anilines (1a-e) with phenol at low temperature in alkaline medium. The resulting dyes have low solubility in aqueous medium due to lack of carboxylic or sulfonic
- Saeed, Aamer,Shabir, Ghulam
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- SILYLATED, SUBSTITUTED BENZOTRIAZOLYLPHENOL COMPOUNDS
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The present invention relates to silylated substituted benzotriazolylphenol compounds of general formula (I) a process for their preparation, a pharmaceutical and/or cosmetic composition comprising these compounds, their use for the preparation of a pharm
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Page/Page column 78-79; 83-84
(2008/12/08)
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- Organosilyl-Benzo-triazole derivatives, processes for their production and their use as UV protecting agents
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The present invention refers to new benzotriazole derivatives, which for their physicochemical properties can be used as UV protection agents. In addition, they can be used to manufacture cosmetic, dermatological, veterinarian as well as pharmaceutical formulations, which protect the skin, lips, nails and hair against UV radiation.
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Page/Page column 14-15
(2010/11/30)
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- Synthesis of new ultraviolet light absorbers based on 2-aryl-2H- benzotriazoles
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A procedure for the synthesis of some new ultraviolet absorbers of the benzotriazole series is reported. The compounds bear a carboxylic or a formyl group para to the hydroxy group, and these functionalities impart to the absorbers improved compatibility with certain disperse dyes on polyester fibers.
- Koutsimpelis, Aristides G.,Screttas, Constantinos G.,Igglessi-Markopoulou, Olga
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p. 1393 - 1401
(2007/10/03)
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- Processes for the preparation of benzotriazole UV absorbers
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Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, for example a trifluoromethyl group, which involves diazotizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means. Also provided is a novel one-pot, multiphase reaction for the preparation of 2(2-nitrophenylazo) substituted phenols, which are precursors for 2H-benzotriazole UV absorbers.
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- Processes for the preparation of benzotriazole UV absorbers
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Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, for example a trifluoromethyl group, which involves diazotizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means. Also provided is a novel one-pot, multiphase reaction for the preparation of 2(2-nitrophenylazo) substituted phenols, which are precursors for 2H-benzotriazole UV absorbers.
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- Process for the preparation of 5-perfluoroalkyl substituted benzotriazole UV absorbers
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A process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, preferably a trifluoromethyl group, involves diazotizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or preferably nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means.
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Page column 12
(2008/06/13)
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- 2H-benzotriazole UV absorders substituted with 1,1-diphenylalkyl groups and compositions stabilized therewith
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2H-Benzotriazole UV absorbers substituted at the 3-position or at the 5-position of the phenyl ring by a 1,1-diphenylalkyl moiety, particularly a 1,1-diphenylethyl group, are particularly photostable in automotive coatings, and are of low color and exhibit low volatility in thermoplastic compositions.
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- Synthesis, characterization and antimicrobial studies of some novel 3- arylazo-7-hydroxy-4-methylcoumarins
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A series of 3-arylazo-7-hydroxy-4-methylcoumarins have been synthesized in excellent yields (80-90%) and their structures established on the basis of IR, 1H NMR, mass spectral data and elemental analyses. Their purity has been ascertained by ch
- Sharma, Pratibha,Pritmani, Shreeya
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p. 1139 - 1142
(2007/10/03)
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- 2-(2-aminophenyl)-acetaldehyde dimethyl acetal: A novel reagent for the protection of carboxylic acids
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The synthesis and use of 2-(2-aminophenyl)-acetaldehyde dimethyl acetal 1 are described. The amides 2, derived from this amine and carboxylic acids, are stable under basic conditions and thus can be regarded as the protected carboxylic acids. The corresponding carboxylic acids are regenerated by conversion of 2 into indolylamides 3 by treatment with CSA and subsequent hydrolysis with LiOOH or NaOH. In addition, 3 can be easily converted to esters, amides, and aldehydes.
- Arai, Eri,Tokuyama, Hidetoshi,Linsell, Martin S.,Fukuyama, Tohru
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- USE OF CURRENTLESS POTENTIAL-TIME CURVES FOR DETERMINING THE RATE CONSTANTS OF DIAZOTATION REACTIONS
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The kinetics and the rate constants for the diazotation of nine aromatic amines at various conditions (temperature, medium) were determined by the method of currentless potential-time curves.A comparison with an independent method and with literature data is presented.
- Dlask, Vladimir
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p. 2315 - 2319
(2007/10/02)
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- Open-chain nitrogen compounds. Part IV. Synthesis of 5-hydroxy-1,2,3-triazoles from 1-aryl-3-(ethoxycarbonylmethyl)triazenes: a new route to α-diazo-N-arylacetamides
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A series of triazenes of type ArN=N-NH-CH2CO2Et, N-arylazoglycine ethyl esters, have been prepared by coupling the arene diazonium salt, ArN2+*X-, with ethyl glycinate, NH2CH2CO2Et; an electron-withdrawing substituent, e.g.NO2, CN, CO2R, and Cl, in the ortho or para position of the aryl group is essential for efficient coupling.The p-substituted arylazoglycine ethyl esters cyclize when treated with alcoholic potassium hydroxide to afford the potassium salts of the 1-aryl-5-hydroxy-1,2,3-triazoles, which can be obtained free by acidification of the potassium salt solution with acetic acid.Reaction of the potassium salts with acetic anhydride yields the 1-aryl-5-acetoxy-1,2,3-triazoles.The 5-hydroxytriazoles, when heated in ethanol, rearrange to α-diazoacetanilides, ArNH*COCHN2.The diazoamides can be obtained in low yield directly from the triazenes by prolonged refluxing in ethanol. o-Substituted aryltriazenes do not cyclize under the same conditions but fragment to the arylamine.
- Baines, Kim M.,Vaughan, Keith,Hooper, Donald R.,Leveck, Lorne F.
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p. 1549 - 1556
(2007/10/02)
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- Synthesis of Substituted Indoles via Meerwein Arylation
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A new method for the synthesis of substituted indoles is detailed.Meerwein arylation of 4- and 6-substituted 2-nitrobenzenediazonium chlorides with vinyl acetate or vinyl bromide and subsequent reductive cyclization of the resulting adducts affords the corresponding 6- and 4-substituted (CH3, OCH3, Cl, Br, CF3) indoles.The diazonium bisulfates of weakly basic 2-nitroanilines (4-Cl, 6-Br, 4-CF3) gave higher yields of Meerwein arylation adducts than the corresponding diazonium chlorides.Coupling of 2-nitrobenzenediazonium chloride with 2-acetoxy-1-alkenes followed byreductive cyclization affords 2-alkylindoles.
- Raucher, Stanley,Koolpe, Gary A.
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p. 2066 - 2069
(2007/10/02)
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- Hydrogen Bonding and Bond Order in Phenylhydrazones: Structures of Diethyl 2-(o-Methylphenylhydrazono)-3-oxopentanedioate (1) and Two Forms of Diethyl 2-(p-Nitrophenylhydrazono)-3-oxopentanedioate
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Reaction of diethyl 3-oxopentanedioate with subtitued benzenediazonium salts in 1:1 ratio gives rise to diethyl 2-(phenylhydrazono)-3-oxopentanedioates.Their IR and 1H NMR spectra have been discussed in terms of the intramolecular hydrogen bonding between
- Drew, Michael G. B.,Vickery, Brian,Willey, Gerald R.
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p. 1530 - 1535
(2007/10/02)
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- 1,2,3-Triazabutadienes. XIV. Investigations into the Acidic Cleavage of the Z-E-Isomeric 1-Aryl-3-- and 1-Aryl-3--triazenes
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The rate of the acid cleavage of the Z-E-isomeric 1-aryl-3-- and 1-aryl-3--triazenes 1 - 5 is investigated in dependence on the substituents in the aryl and benzo residue.The Z-isomer
- Fanghaenel, E.,Hohlfeld, J.
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p. 253 - 261
(2007/10/02)
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- Synthesis, spectral and structural studies, and an evaluation of the hydrogen bonding of some phenylhydrazones
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A series of 46 phenylhydrazones, some novel, containing a variety of structural types has been synthesised. These have been studied by 1H n.m.r. and i.r. spectroscopy with respect to potential inter- and intra-molecular hydrogen bonding. ortho-Nitro or -carbonyl groups form strong hydrogen bonds to the imino-group which are readily observed by 1H n.m.r. but not by i.r. spectroscopy. 'Terminal' carbonyl groups also form strong hydrogen bonds to the imino-group and these can be detected by both i.r. and 1H n.m.r. spectroscopy. When both ortho-nitro- or -carbonyl groups and 'terminal' carbonyl groups are present the imino hydrogen atom is doubly hydrogen bonded and this is apparent in the 1H n.m.r. spectrum. The formation of an intramolecular hydrogen bond in the phenylhydrazone prevents the formation of an intermolecular hydrogen bond between the phenylhydrazone and a polar solvent.
- Kaberia, Festus,Vickery, Brian,Willey, Gerald R.,Drew, Michael G. B.
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p. 1622 - 1626
(2007/10/02)
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