5307-14-2Relevant articles and documents
Protonation of Cationic Bases in Perchloric Acid: Establishment of the H+ Scale in 0-11 M Perchloric Acid
Lovell, Michael W.,Vogt, Brian S.,Schulman, Stephen G.
, p. 1885 - 1888 (1984)
The protonation of several monocationic bases in perchloric acid was studied with UV-visible absorption spectroscopy.The H+ scale in perchloric acid was established by using primary amine cationic bases as indicators.It was found that the H+ scale in perchloric acid is more negative than in sulfuric acid.The acid-dissociation constants for compounds studied in both acids were found to be in reasonably good agreement with each other.
[1+1] Copper(II) macrocyclic Schiff base complex on rGO as a photocatalyst for reduction of nitroaromatics compounds under visible-light irradiation
Ghalebin, Saeed Nasiri,Bezaatpour, Abolfazl,Sadr, Moayad Hossaini,Sadjadi, Mirabdullah Seyed,Moghaddam, Mohammad Khodadadi,Szunerits, Sabine
, (2021/01/26)
In this work, [1 + 1] macrocyclic Copper(II) Schiff base complex ([CuL](NO3)2.H2O) was synthesized and grafted on reduced graphene oxide successfully. The novel prepared sample was characterized by physico-chemical techniques and used as a photocatalyst for the reduction of nitroaromatic compounds to their amine derivatives at room temperature under visible-light irradiation with hydrazine mono hydrate. From the prepared samples, reduced graphene oxide loaded with 30% [CuL](NO3)2.H2O catalyst (rGO/CuM30) shows the best efficiency for converting different nitroaromatic compounds to the corresponding amino compounds using visible light. As-prepared catalyst illustrated excellent activity for the reduction of 2-nitrophenol to 2-aminophenol (100% conversion) in only 90 min. Finally, the catalyst could be recovered for five times and reused without decreasing of its efficiency.
Gold supported on titania for specific monohydrogenation of dinitroaromatics in the liquid phase
Liu, Shuang-Shuang,Liu, Xiang,Yu, Lei,Liu, Yong-Mei,He, He-Yong,Cao, Yong
, p. 4162 - 4169 (2014/09/29)
Liquid-phase selective monohydrogenation of various substituted dinitroaromatics to the corresponding valuable nitroanilines was investigated on gold-based catalysts. Special attention was paid to the effect of Au particle size on this monoreduction reaction. Interestingly, TiO2 supported gold catalysts containing a relatively larger mean Au particle size (>5 nm) showed far superior chemoselectivity for specific mono-hydrogenation of dinitroaromatics, with the highest performance attainable for the catalyst bearing Au particles of ca. 7.5 nm. Results in the intermolecular competitive hydrogenation showed that the intrinsic higher accumulation rates of the desired nitroanilines associated with the catalyst possessing larger Au particles were responsible for the high chemoselectivity observed. the Partner Organisations 2014.
A new class of heterogeneous platinum catalysts for the chemoselective hydrogenation of nitroarenes
Pandarus, Valerica,Ciriminna, Rosaria,Beland, Francois,Pagliaro, Mario
scheme or table, p. 1306 - 1316 (2011/06/25)
A new series of nanostructured platinum catalysts able to catalyze the selective reduction of nitroarenes has been developed. The materials, made of organosilica physically doped with nanostructured platinum(0), are stable and efficient. Reactions in general proceed with high yield and often go to completion, while the catalysts can be reused in further reaction runs. This establishes a new class of relevant solid catalysts for synthetic organic chemistry named SiliaCat Platinum-Hydrogel.
Selective partial hydrogenation of dinitrobenzenes to nitroanilines catalyzed by Ru/C
Hou, Jie,Ma, Yonghuan,Li, Yuhan,Guo, Fang,Lu, Lianhai
scheme or table, p. 974 - 975 (2009/04/06)
Ru/C was found to be a highly effective catalyst for the selective partial hydrogenation of a range of dinitrobenzenes to their corresponding nitroanilines with excellent selectivity under mild conditions. Furthermore, the effect from other substitute groups of dinitrobenzenes on partial hydrogenation was also explored in this study. Copyright
One step hair coloring compositions using salts
-
, (2008/06/13)
A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.
Transition metal complexes as dye forming catalysts in hair coloring compositions
-
, (2008/06/13)
A hair coloring composition comprising a first composition which comprises: (a) a dye forming transition metal salt or complex; which is first applied to the hair; and a second composition which comprises the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an aminophenol, a polyhydric phenol a catechol and mixtures thereof.
Unusual reaction of 1,4-diamino-2-nitrobenzene derivatives toward nucleophiles: Catalysis by sodium sulphite
Forlani, Luciano,Boga, Carla,Mazza, Milena,Cavrini, Vanni,Andrisano, Vincenza
, p. 4647 - 4654 (2007/10/03)
Unusual substitution of amino group occurs by reactions of some 1,4diamino-2-nitrobenzenes (semipermanent hair dyes) and nucleophiles (NH3, H2O). The reaction is catalyzed by sodium sulfite. The obtained products are suspected of being toxic substances which may be present in cosmetic matrices. Apparently, this reaction is a nucleophilic aromatic substitution but it may be explained by a mechanism involving a tautomeric form of substrate.
Hypoxia-Selective Agents Derived from Quinoxaline 1,4-Di-N-oxides
Monge, Antonio,Palop, Juan A.,Cerain, Adela Lopez de,Senador, Virginia,Martinez-Crespo, Francisko J.,et al.
, p. 1786 - 1792 (2007/10/02)
Hypoxic cells, which are a common feature of solid tumors, but not normal tissues, are resistant to both anticancer drugs and radiation therapy.Thus the identification of drugs with selective toxicity toward hypoxic cells is an important objective in anticancer chemotherapy.The benzotriazine di-N-oxide (SR 4233, Tirapazamine) has been shown to be an efficient and selective cytotoxin for hypoxic cells.Since the bioreductive activation of Tirapazamine is thought to be due to the presence of the 1,4-di-N-oxide moiety, a series of 3-aminoquinoxaline-2-carbonitrile 1,4-di-N-oxides with a range of electron-donating and -withdrawing substituents in the 6- and /or 7- positions has been synthesized and evaluated for toxicity to hypoxic cells.Electrochemical studies of the quinoxaline di-N-oxides and Tirapazamine showed that as the electron-withdrawing nature of the 6(7)-substituent increases, the reduction potential becomes more positive and the compound is more readily reduced.Apart from the unsubstituted 6a and the 6,7-dimethyl derivative 6c, the quinoxaline di-N-oxide have reduction potentials significantly more positive than Tirapazamine (Epc -0.90 V).The most potent cytotoxins to cells in culture were the 6,7-dichloro and 6,7-difluoro derivatives 6i and 6l, which were 30-fold more potent than Tirapazamine.The 6(7)-fluoro and 6(7)-chloro compounds, 6e and 6h, showed the greatest hypoxia selectivity.Four of the compounds, 6e, 6f, 6h and 6i, killed the inner cells of multicellular tumor spheroids in vitro.In vivo Balb/c mice tolerated a dose of these four compounds twice the size of that of Tirapazamine.This study demonstrates that quinoxaline 1,4-di-N-oxides could provide useful hypoxia-selective therapeutic agents.
Hair dye preparations containing substantive nitrodiphenylamine derivatives
-
, (2008/06/13)
This invention encompasses compounds of the formula: STR1 wherein: one of R1 or R2 is nitro and the other is --SO3 H or COOH; and one of R3 or R4 is hydrogen and the other is --NR5 R6, where R5 and R6 independently are hydrogen, C1-4 alkyl, or C2-4 hydroxyalkyl; or a water soluble salt thereof; hair dye preparations containing the above compounds as substantive hair dyes; and methods for dyeing hair using such preparations.
