- Commercial Pd/C-Catalyzed N-Methylation of Nitroarenes and Amines Using Methanol as Both C1 and H2 Source
-
Herein, we report commercially available carbon-supported-palladium (Pd/C)-catalyzed N-methylation of nitroarenes and amines using MeOH as both a C1 and a H2 source. This transformation proceeds with high atom-economy and in an environmentally friendly way via borrowing hydrogen mechanism. A total of >30 structurally diverse N-methylamines, including bioactive compounds, were selectively synthesized with isolated yields of up to 95%. Furthermore, selective N-methylation and deuteration of nimesulide, a nonsteroidal anti-inflammatory drug, were realized through the late-stage functionalization.
- Goyal, Vishakha,Gahtori, Jyoti,Narani, Anand,Gupta, Piyush,Bordoloi, Ankur,Natte, Kishore
-
p. 15389 - 15398
(2019/12/04)
-
- Highly Selective N-Monomethylanilines Synthesis from Nitroarene and Formaldehyde via Kinetically Excluding of the Thermodynamically Favorable N,N-Dimethylation Reaction
-
The synthesis of N-monomethylamine remains a challenging topic because the N,N-dimethylation reaction is thermodynamically favorable. In this work, the kinetically controlled N-monomethylamine synthesis from nitroarene and paraformaldehyde/H2 is reported to have superhigh N-monomethylamine selectivity in the presence of a Pd/TiO2 catalyst. The superior selectivity should be attributed to the preferential adsorption of the primary amine over N-monomethylamine on the Pd/TiO2 surface, as elucidated by NH3/Me2NH-TPD, while the excellent catalytic activity could be associated with the good H2 activation ability and high amine adsorbing capacity of the catalyst, as elucidated by NH3-TPD and H2-TPR tests. Good results were obtained with a variety of nitroarenes containing methyl, methoxyl, hydroxyl, fluoride, trifluoromethyl, ester, and amide substituents as starting materials, and the potential synthetic utility of this protocol in pharmaceutical is illustrated by N-monomethylation of drug molecules, such as clinidipine, nimesulide, procaine, and methyl aminosalicylate.
- Wang, Hongli,Yuan, Hangkong,Yang, Benqun,Dai, Xingchao,Xu, Shan,Shi, Feng
-
p. 3943 - 3949
(2018/05/23)
-
- Method for selectively preparing N-monomethylamine compounds by using nitro compound as raw material
-
The invention discloses a method for selectively preparing N-monomethylamine compounds by using a nitro compound as a raw material. The method uses the nitro compound as the reaction raw material, formaldehyde as a methylating agent and a hydrogen gas as a reducing agent, in the presence of a supported type catalyst, a reaction is performed for 2-48 h at temperature of 10-180 DEG C in a reaction medium, and therefore the N-monomethylamine compounds are obtained, wherein the catalyst is at least one catalyst supported by palladium, platinum, ruthenium or rhodium. The method disclosed by the invention is simple, and can obtain the target product in a low-cost high-yield and high-selectivity manner; the method simplifies reaction steps, improves reaction efficiency, reduces reaction costs, and avoids separation of an intermediate product primary amine with high toxicity, easy deterioration and difficult storage; the method adopts the H2 as the reducing agent, thereby being clean, inexpensive and environmentally friendly; and the reaction conditions of the method are mild, and the catalyst is non-corrosive and easy to separate and reuse.
- -
-
Paragraph 0035; 0036
(2018/11/03)
-
- A series of BiO: XIy/GO photocatalysts: Synthesis, characterization, activity, and mechanism
-
A series of bismuth oxyiodide (BiOxIy)-grafted graphene oxide (GO) sheets with different GO contents were synthesized through a simple hydrothermal method. This is the first report where four composites of BiOI/GO, Bi4O5I2/GO, Bi7O9I3/GO, and Bi5O7I/GO have been characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. The assembled BiOxIy/GO composites exhibited excellent photocatalytic activities in the degradation of crystal violet (CV) under visible light irradiation. The order of rate constants was as follows: Bi7O9I3/GO > Bi4O5I2/GO > Bi4O5I2 > Bi7O9I3 > Bi5O7I/GO > BiOI/GO > BiOI > Bi5O7I > GO. The photocatalytic activity of the Bi7O9I3/GO (or Bi4O5I2/GO) composite reached a maximum rate constant of 0.351 (or 0.322) h-1, which was 1.8 (or 1.7) times higher than that of Bi7O9I3 (or Bi4O5I2), 6-7 times higher than that of BiOI/GO, and 119-130 times higher than that of BiOI. The quenching effects of different scavengers and electron paramagnetic resonance demonstrated that the superoxide radical (O2-) played a major role and holes (h+) and hydroxyl radicals (OH) played a minor role as active species in the degradation of crystal violet (CV) and salicylic acid (SA). Possible photodegradation mechanisms are proposed and discussed in this research.
- Chou, Shang-Yi,Chung, Wen-Hsin,Chen, Li-Wen,Dai, Yong-Ming,Lin, Wan-Yu,Lin, Jia-Hao,Chen, Chiing-Chang
-
p. 82743 - 82758
(2016/11/01)
-
- N-Alkylation of Alkylolamines with Alcohols Over Mesoporous Solid Acid–Base Cs–B–Zr Catalyst
-
Abstract: The mesoporous solid acid–base Cs–B–Zr mixed oxides were synthesized using the co-precipitation method followed by a subsequent thermal treatment. The catalytic activity of solid Cs–B–Zr mixed oxide was tested for solvent free acid–base catalysed direct alkylolamines with alcohols as green alkylating agent. The effects of Cs/B/Zr ratio, calcination temperature, reaction conditions, and reaction substrate on the catalytic performance of the catalysts were investigated. The XRD, N2 adsorption–desorption, ICP-OES, FT-IR and NH3/CO2-TPD results showed that the mesoporous structure and acid–base properties of the catalysts play important roles in the reaction. A suitable number of acid and basic sites on the catalyst lead to a high activity for the N-alkylation reaction. Graphical Abstract: A direct N-alkylation of amino alcohol with alcohols has been developed using mixed oxide Cs–B–Zr as an acid–base bifunctionalized catalyst.[Figure not available: see fulltext.]
- Chen, Aimin,Wang, Houyong,Liu, Rui,Bo, Yingying,Hu, Jun
-
p. 1182 - 1193
(2016/07/06)
-
- Room-temperature copper-catalyzed arylation of dimethylamine and methylamine in neat water
-
The first room-temperature copper-catalyzed arylations of dimethylamine and methylamine in neat water have been developed. Using a combination of CuI and 6,7-dihydroquinolin-8(5 H)-one oxime as catalyst, dimethylamine is arylated with various aryl halides to give the corresponding products in good to excellent yields. Further, this catalysis enables the selective arylation of methylamine to afford the high yields of monoarylated methylamines as the sole products.
- Wang, Deping,Kuang, Daizhi,Zhang, Fuxing,Yang, Chunlin,Zhu, Xiaoming
-
supporting information
p. 714 - 718
(2015/03/18)
-
- A switchable [2]rotaxane asymmetric organocatalyst that utilizes an acyclic chiral secondary amine
-
A rotaxane-based switchable asymmetric organocatalyst has been synthesized in which the change of the position of the macrocycle reveals or conceals an acyclic, yet still highly effective, chiral organocatalytic group. This allows control over both the rate and stereochemical outcome of a catalyzed asymmetric Michael addition.
- Blanco, Victor,Leigh, David A.,Marcos, Vanesa,Morales-Serna, José A.,Nussbaumer, Alina L.
-
supporting information
p. 4905 - 4908
(2014/04/17)
-
- Demethylation of aromatic methyl ethers using ionic liquids under microwave irradiation
-
An efficient demethylation reaction for aromatic methyl ethers has been developed. Deprotection reactions give high yields with butylpyridinium bromide under microwave irradiation. Basic and acidic functional groups are tolerated if the reaction is performed under acidic conditions.
- Passiniemi, Mikko,Myllymaeki, Mikko J.,Vuokko, Juha,Koskinen, Ari M.P.
-
scheme or table
p. 48 - 52
(2012/04/10)
-
- Layered double hydroxide-supported l-methionine-catalyzed chemoselective o-methylation of phenols and esterification of carboxylic acids with dimethyl carbonate: A "green" protocol
-
" Chemical equation presented" Simple methodology: A layered double hydroxide-supported L-methionine (LDH-Met) catalyst is designed in a simple methodology to explore its synthetic utility in biologically relevant reactions. The organocatalyst is characterized by FT-IR, TGA/DTA, powder XRD, and EDX spectroscopic techniques. This material has been successfully utilized for the preparation of aryl methyl ethers and esters from the corresponding phenols and carboxylic acids, respectively, in moderate to high yields (see scheme).
- Dhakshinamoorthy, Amarajothi,Sharmila, Alagarsamy,Pitchumani, Kasi
-
supporting information; experimental part
p. 1128 - 1132
(2010/06/13)
-
- Fast deprotection of phenoxy benzyl ethers in transfer hydrogenation assisted by microwave
-
Phenoxy benzyl ethers are easily and quickly deprotected in the presence of ammonium formate and microencapsulated Pd(0)EnCat with the assistance of microwave irradiation. This procedure can be applied in the presence of other functional groups as well. The described protocol is particularly convenient for the preparation in a parallel and automatic fashion of libraries of compounds possessing a phenol type moiety.
- Quai, Monica,Repetto, Claudio,Barbaglia, Walter,Cereda, Enzo
-
p. 1241 - 1245
(2007/10/03)
-
- Mono-N-methylation of functionalized anilines with alkyl methyl carbonates over NaY faujasites. 4. Kinetics and selectivity
-
(Chemical Equation Presented) In the presence of NaY faujasite as the catalyst, the reaction of bifunctional anilines (1-4: XC6H 4-NH2; X = OH, CO2H, CH2OH, and CONH2) with methyl alkyl carbonates [MeOCO2R′: R′ = Me or MeO(CH2)2O(CH2)2] proceeds with a very high mono-N-methyl selectivity (XC6H 4NHMe up to 99%), and chemoselectivity as well, with other nucleophilic functions (OH, CO2H, CH2OH, CONH2) fully preserved from alkylation and/or transesterification reactions. Aromatic substituents, however, modify the relative reactivity of amines 1-4: good evidence suggests that, not only steric and electronic effects, but, importantly, direct acid-base interactions between substituents and the catalyst are involved. Weakly acidic groups (OH, CH2OH, CONH2, pKa ≥ 10) may help the reaction, while aminobenzoic acids (pK a of 4-5) are the least reactive substrates. The solvent polarity also affects the reaction, which is faster in xylene than in the more polar diglyme. The mono-N-methyl selectivity is explained by the adsorption pattern of reagents within the zeolite pores: a BAl2 displacement of the amine on methyl alkyl carbonate should occur aided by the geometric features of the NaY supercavities. Different factors account for the reaction chemoselectivity. Evidence proves that the polarizability of the two nucleophilic terms (NH 2 and X groups) of anilines is relevant, although adsorption and confinement phenomena of reagents promoted by the zeolite should also be considered.
- Selva, Maurizio,Tundo, Pietro,Foccardi, Tommaso
-
p. 2476 - 2485
(2007/10/03)
-
- Synthesis of mono-N-substituted functionalized anilines
-
The present invention relates to a process for direct and selective synthesis of mono-N-substituted functionalized anilines by using alkylating agents selected from the class of organic carbonates, preferably of the dialkyl, dibenzyl and diallyl types, in the presence of suitable catalysts that are chemically related to the class of aluminosilicates.
- -
-
-
- Synthesis of mono-N-substituted functionalized anilines
-
The present invention relates to a process for direct and selective synthesis of mono-N-substituted functionalized anilines by using alkylating agents selected from the class of organic carbonates, preferably of the dialkyl, dibenzyl and diallyl types, in the presence of suitable catalysts that are chemically related to the class of aluminosilicates.
- -
-
-
- 1,3-Dihydroxybenzene derivatives and colorants containing said compounds
-
1,3-Dihydroxybenzene derivatives of general formula (I) or (Ia) or physiologically tolerated, water-soluble thereof wherein R′1 denotes substituted pyridyl group, a pyrimidyl group, a group of formula (IIa) or (IIIa) and the dyeing agents for keratin fibers containing these compounds.
- -
-
-
- One step hair coloring compositions using salts
-
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.
- -
-
-
- Reaction of functionalized anilines with dimethyl carbonate over NaY faujasite. 3. Chemoselectivity toward mono-N-methylation
-
In the presence of NaY faujasite, dimethyl carbonate (MeOCO2Me, DMC) is a highly chemoselective methylating agent of functionalized anilines such as aminophenols (1), aminobenzyl alcohols (2), aminobenzoic acids (3), and aminobenzamides (4). The reaction proceeds with the exclusive formation of N-methylanilines without any concurrent O-methylation or N-/O-methoxy carbonylation side processes. Particularly, only mono-N-methyl derivatives [XC6H4NHMe, X = o-, m-, and p-OH; o- and p-CH 2OH; o- and P-CO2H; o- and p-CONH2] are obtained with selectivity up to 99% and isolated yields of 74-99%. DMC, which usually promotes methylations only at T > 120 °C, is activated by the zeolite catalyst and it reacts with compounds 1, 2, and 4, at 90 °C. Aminobenzoic acids (3) require a higher reaction temperature (≥130 °C).
- Selva, Maurizio,Tundo, Pietro,Perosa, Alvise
-
p. 7374 - 7378
(2007/10/03)
-
- Transition metal complexes as dye forming catalysts in hair coloring compositions
-
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.
- -
-
-
- Hair colouring and conditioning compositions
-
A hair colouring and conditioning composition comprising: (a) a hair colouring agent; and (b) a hair conditioning agent; wherein the composition provides an Average Combing Index Value of greater than 1.2 as measured by the Combing Technical Test Method. The products can provide excellent hair colouring together with excellent conditioning, reduced hair damage, brittleness and dryness, and is convenient and easy to use.
- -
-
-
- Hair conditioning compositions and their use in hair colouring compositions
-
The present invention relates to a hair care composition comprising a aminofunctional polysiloxane having a specified average effective particle size which provides improved durable conditioning particularly when utilised in conjunction with a hair colouring composition.
- -
-
-
- HAIR COLORING COMPOSITIONS
-
A hair coloring composition comprising: (a) from about 0.0003 moles (per 100 g of composition) to less than about 0.09 moles (per 100 g of composition) of an inorganic peroxygen oxidizing agent; and (b) an oxidative hair coloring agent; wherein the pH of each of (a) and (b) is in the range of from about 1 to about 6 and wherein the combined mixture of (a) and (b) has a pH in the range of from about 1 to about 6. The products can provide excellent hair coloring and in-use efficacy benefits including excellent initial color and good wash fastness in combination with reduced hair damage at low pH.
- -
-
-
- HAIR COLORING COMPOSITIONS
-
A hair coloring composition comprising: (a) a preformed organic peroxyacid oxidising agent; and (b) an oxidative hair coloring agent; wherein the pH of each of components (a) and (b) is in the range of from about pH 1 to less than about pH 7 and wherein the pH of the composition is in the range of from about pH 1 to less than about pH 7. The products can provide excellent hair coloring and in-use efficacy benefits including excellent initial color and good wash fastness in combination with reduced hair damage at low pH.
- -
-
-
- Oxidation of xenobiotics by plant microsomes, a reconstituted cytochrome P450 system and peroxidase: A comparative study
-
The microsomal fraction from tulip bulbs (Tulipa fosteriana, L.) contains cytochrome P450 (CYP3, EC 1.14.14.1) and peroxidase (EC 1.11.1.7.) enzymes catalyzing the NADPH - and hydrogen peroxide - dependent oxidation of the xenobiotic substrates, N-nitrosodimethylamine (NDMA), N- nitrosomethylaniline (NMA), aminopyrine and 1-phenylazo 2-hydroxynaphthalene (Sudan I), respectively. Oxidation of these model xenobiotics has also been assessed in a reconstituted electron-transport chain with a partially purified CYP fraction, phospholipid and isolated tulip NADPH:CYP reductase (EC 1.6.2.4.). Peroxidase isolated from tulip bulbs (isoenzyme C) oxidizes these xenobiotics, too. Values of kinetic parameters (K(m), V(max)), requirements for cofactors (NADPH, hydrogen peroxide), the effect of inhibitors and identification of products formed from the xenobiotics by the microsomal fraction, partially purified CYP and peroxidase C were determined. These data were used to estimate the participation of the CYP preparation and peroxidase C in oxidation of two out of the four studied xenobiotics (NMA, Sudan I) in tulip microsomes. Using such detailed study, we found that the CYP-dependent enzyme system is responsible for the oxidation of these xenobiotics in the microsomal fraction of tulip bulbs. The results demonstrate the progress in resolving the role of plant CYP and peroxidase enzymes in oxidation of xenobiotics. (C) 2000 Elsevier Science Ltd.
- Stiborova,Schmeiser,Frei
-
p. 353 - 362
(2007/10/03)
-
- Peptidyl N-nitrosoanilines: A novel class of cysteine protease inactivators
-
A series of peptidyl N-nitrosoanilines were designed, synthesized, and evaluated as inactivators of cysteine protease papain and serine protease chymotrypsin. These new compounds exhibited different inhibitory activities toward the cysteine protease papain in a time- and concentration-dependent manner with second-order rate constants (κ(inact)/K1) ranging over 2 orders of magnitude from 0.604 M-1 s-1 (1) to 100.36 M-1 s-1 (7). No inactivation was observed for serine protease chymotrypsin. Formation of the S-NO bond in papain is supported by several lines of evidences from both spectroscopic studies and chemical analyses. The pH profile more insight into the mechanism of the inactivation process. The covalent yet recoverable cysteine protease inactivation process offers mechanistic implications and endows this new family of inactivators with special properties that are suitable for the development of stable and potent cysteine protease inhibitors.
- Guo, Zhengmao,Ramirez, Johnny,Li, Jun,Wang, Peng George
-
p. 3726 - 3734
(2007/10/03)
-
- Synthesis and antiarrhythmic and parasympatholytic properties of substituted phenols. 3. Modifications to the linkage region (region 3)
-
As part of a continuing program of systematically modifying the structure of the class I antiarrhythmic drug changrolin, we synthesized 15 analogues in which the linkage between the two aromatic regions was altered. High antiarrhythmic activity and low parasympatholytic activity was found when the linkage region, designated region 3, contained a carbonyl moiety, including ketones, amides, and ureas. Secondary amides were superior to tertiary amides, while amide reversal resulted in no change in activities. One compound in this series, 2,6-bis(1-pyrrolidinyl-methyl)-4-benzamidophenol (ACC-9358), is undergoing preclinical evaluations.
- Stout,Matier,Barcelon-Yang,Reynolds,Brown
-
p. 295 - 298
(2007/10/02)
-
- THE INTERVENTION OF OXYGEN IN THE OXIDATION OF N,N-DIMETHYLANILINES WITH FENTON'S REAGENT
-
N-Dealkylation and nuclear hydroxylation are observed in the treatment of N,N-dimethylanilines with iron(II) and hydrogen peroxide.Oxygen is consumed during the oxidation.Although oxygen activation depends upon pH and concentration of both substrate and hydrogen peroxide, deuterium labelling of substrates and measurements of oxygen consumption provide some information on the mechanism of its activation.
- Galliani, Guido,Rindone, Bruno
-
p. 207 - 212
(2007/10/02)
-
- One-Electron Redox Potentials of Phenols. Hydroxy- and Aminophenols and Related Compounds of Biological Interest
-
The rate constants for reversible electron transfer between a series of substituted phenolate ions and anilines and various substituted phenoxyl or anilino radicals in aqueous solution were measured by observing the formation or depletion of the radicals involved.Nonequilibrium concentrations of the radicals were produced in the presence of the corresponding phenols or anilines by using the pulse radiolysis technique.The relaxation of the system to equilibrium was monitored by optical detection methods.From the equilibrium constants for one-electron transfer, the one-electron redox potentials (E2) for 38 phenolic or anilino type compounds were determined, many of which are natural products.The redox potentials are strongly influenced by electron-donating or -withdrawing substituents at the aromatic system.
- Steenken, S.,Neta, P.
-
p. 3661 - 3667
(2007/10/02)
-