cas 504-24-5, 4-Aminopyridine | Articles data

Articles about 504-24-5Total 87 be found

Article title
Article abstract
Author
Journal number and time
Download

Crystal Engineering in Supramolecular Polyoxometalate Hybrids through pH Controlled in Situ Ligand Hydrolysis
A family of five different three-dimensional polyoxometalate (POM) based supramolecular hybrids were synthesized by a hydrothermal route under different pH using a hydrolyzable naphthalene diimide ligand. The mechanism of crystallographic phase variation of the POM-amino pyridine hybrids under different pH was studied through controlled experiments where the final hydrolyzed products were analyzed through NMR and single crystal X-ray diffraction. Different pH conditions led to variation in the extent of protonation and hydrolyzation of the ligand, yielding different phases. All of these were identified, and the structures of the supramolecular hybrids were characterized extensively. Mechanistic study proved that only the reaction conditions are responsible for the hydrolysis of the ligand and the in situ generated POM species do not have any role in it. Magnetic measurements confirmed the hexavalent oxidation states of the transition metal center (Mo) in the POM. Optical band gap measurements revealed that these hybrids are semiconducting in nature. Two of the compounds were studied for hydrogen peroxide mediated selective oxidation catalysis of small organic molecules and found to exhibit very good activity with high percentage of selectivity for the desired products of industrial importance.
Roy, Soumyabrata,Mumbaraddi, Dundappa,Jain, Ankit,George, Subi J.,Peter, Sebastian C.
p. 590 - 601
(2018)
Read Online

-
-
Boer,den Hertog
p. 1943
(1969)
Read Online

Indirect reduction of CO2and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes
The reduction of polar bonds, in particular carbonyl groups, is of fundamental importance in organic chemistry and biology. Herein, we report a manganese pincer complex as a versatile catalyst for the transfer hydrogenation of amides, carbamates, urea derivatives, and even polyurethanes leading to the corresponding alcohols, amines, and methanol as products. Since these compound classes can be prepared using CO2as a C1 building block the reported reaction represents an approach to the indirect reduction of CO2. Notably, these are the first examples on the reduction of carbamates and urea derivatives as well as on the C-N bond cleavage in amides by transfer hydrogenation. The general applicability of this methodology is highlighted by the successful reduction of 12 urea derivatives, 26 carbamates and 11 amides. The corresponding amines, alcohols and methanol were obtained in good to excellent yields up to 97%. Furthermore, polyurethanes were successfully converted which represents a viable strategy towards a circular economy. Based on control experiments and the observed intermediates a feasible mechanism is proposed.
Liu, Xin,Werner, Thomas
p. 10590 - 10597
(2021/08/20)

Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
supporting information
p. 1618 - 1629
(2021/01/25)

Heterogeneous photocatalysis of azides: Extending nitrene photochemistry to longer wavelengths
The photodecomposition of azides to generate nitrenes usually requires wavelengths in the 300 nm region. In this study, we show that this reaction can be readily performed in the UVA region (368 nm) when catalyzed by Pd-decorated TiO2. In aqueous medium the reaction leads to amines, with water acting as the H source; however, in non-protic and non-nucleophilic media, such as acetonitrile, nitrenes recombine to yield azo compounds, while azirine-mediated trapping occurs in the presence of nucleophiles. The heterogeneous process facilitates catalyst separation while showing great chemoselectivity and high yields.
Argüello, Juan E.,Lanterna, Anabel E.,Lemir, Ignacio D.,Scaiano, Juan C.
supporting information
p. 10239 - 10242
(2020/10/02)

Preparation method and post-treatment process of 4-aminopyridine
The invention relates to a preparation method and a post-treatment process of 4-aminopyridine. The preparation method comprises the following steps: with isonicotine as an initial raw material, carrying out a Hofmann degradation reaction in a sodium hypochlorite solution and a sodium hydroxide solution, carrying out cooling treatment on a reaction solution, and then successively performing activated carbon decoloration, cooling crystallization, vacuum filtration and drying, and secondary recrystallization and drying to obtain a final 4-aminopyridine product. The whole reaction conditions are mild and easy to control, the operation is simple, the purity of the 4-aminopyridine reaches 99% or above, and the post-treatment process is simple, convenient and easy to operate, has a total yield of90% or above and is a post-treatment technology suitable for industrial production and application.
-
Paragraph 0021-0039

(2020/06/02)

Preparation method of pyridine derivative (by machine translation)
To the method, piperidine-4-one hydrochloride is used as a raw material, and a series of pyridine derivatives are obtained through halogenation reaction and elimination reaction. The reaction is eliminated by reacting piperidine-4-one hydrochloride with a specific amount of the 3,5 - halogenating agent in a halogenation 3, 3, 5 - reaction with a halogen-3, 3, 5, 5 - based reaction, followed by reaction with a pyridine derivative of a hydroxyl group, an amino group 4 - or a dimethylamino group, respectively, by eliminating the reaction with a different kind of basic agent. The method is simple and convenient to operate, mild in condition, short in technological process, low in waste water yield, environment-friendly, low in cost and beneficial to green industrial production of the pyridine derivative. (by machine translation)
-
Paragraph 0079-0082

(2019/12/02)

Direct conversion of phenols into primary anilines with hydrazine catalyzed by palladium
Primary anilines are essential building blocks to synthesize various pharmaceuticals, agrochemicals, pigments, electronic materials, and others. To date, the syntheses of primary anilines mostly rely on the reduction of nitroarenes or the transition-metal-catalyzed Ullmann, Buchwald-Hartwig and Chan-Lam cross-coupling reactions with ammonia, in which non-renewable petroleum-based chemicals are typically used as feedstocks via multiple step syntheses. A long-standing scientific challenge is to synthesize various primary anilines directly from renewable sources. Herein, we report a general method to directly convert a broad range of phenols into the corresponding primary anilines with the cheap and widely available hydrazine as both amine and hydride sources with simple Pd/C as the catalyst.
Qiu, Zihang,Lv, Leiyang,Li, Jianbin,Li, Chen-Chen,Li, Chao-Jun
p. 4775 - 4781
(2019/05/16)

Photocatalytic hydrogenation of nitroarenes: supporting effect of CoOx on TiO2 nanoparticles
Cobalt oxide visible light-active photo-catalysts supported on TiO2 nanoparticles with varying amount of cobalt oxide [3% CoOx/TiO2 (A), 4% CoOx/TiO2 (B), 5% CoOx/TiO2 (C)] were synthesized by solid-state method followed by calcination. The as-synthesized catalysts were characterized by various techniques such as powder XRD, TEM, EDX, UV-Vis-DRS and XPS analysis. The photocatalytic activity of the as-synthesized materials was studied for the reduction of nitroarenes to the corresponding amines using hydrazine monohydrate as the reductant. Cobalt(ii) oxide is responsible for the reduction of nitroarenes and then, cobalt(iii) is reduced back to the original compound by hydrazine hydrate, thus ascertaining the catalytic nature of this hydrogenation process. XPS suggests the presence of Co(ii) in CoOx/TiO2.
Amanchi, Srinivasa Rao,Ashok Kumar,Lakshminarayana, Bhairi,Satyanarayana,Subrahmanyam
p. 748 - 754
(2019/01/10)

Copper(ii)-catalyzed c-n coupling of aryl halides and n-nucleophiles promoted by quebrachitol or diethylene glycol
Herein, we report the natural ligand quebrachitol (QCT) as a promoter for a Cu(II) catalyst, which is highly effective for N-Arylation of various amines and related aryl halides. A series of diarylamine derivatives were obtained in high yields by using diethylene glycol (DEG) as both ligand and solvent. The C-N coupling reactions proceed under mild conditions and exhibit good functional group tolerance.
Chen, Guoliang,Chen, Yuanguang,Du, Fangyu,Fu, Yang,Wu, Ying,Zhou, Qifan
supporting information
p. 2161 - 2168
(2019/11/25)

Simple Nickel Salts for the Amination of (Hetero)aryl Bromides and Iodides with Lithium Bis(trimethylsilyl)amide
Recent developments in the chemistry of C-N bond formation and the synthesis of anilines have allowed for the use of first-row transition metals to catalyze these transformations. Much of the progress in this area has been driven by comprehensive screening for privileged/tailored ligands, which can be costly and not readily available in a research laboratory setting. In this communication we report a protocol in which simple nickel salts catalyze the C-N cross-coupling reaction between (hetero)aryl bromides and iodides with lithium bis(trimethylsilyl)amide without the need for any additive ligand. This method is amenable to low nickel catalyst loadings (1%) as well as gram-scale reactions. Because of the good functional group tolerance and compatibility with heterocyclic moieties, this method is useful for academic laboratory settings where access to tailored ligands and noble-metal catalysts could be challenging.
Martinez, Gabriel Espinosa,Nugent, Joseph W.,Fout, Alison R.
supporting information
p. 2941 - 2944
(2018/09/21)

An amine protecting group deprotectable under nearly neutral oxidative conditions
The 1,3-dithiane-based dM-Dmoc group was studied for the protection of amino groups. Protection was achieved under mild conditions for aliphatic amines, and under highly reactive conditions for the less reactive arylamines. Moderate to excellent yields were obtained. Deprotection was performed by oxidation followed by treating with a weak base. The yields were good to excellent. The new amino protecting group offers a different dimension of orthogonality in reference to the commonly used amino protecting groups in terms of deprotection conditions. It is expected to allow a collection of transformations to be carried out on the protected substrates that are unattainable using any known protecting groups.
Shahsavari, Shahien,McNamara, Chase,Sylvester, Mark,Bromley, Emily,Joslin, Savannah,Lu, Bao-Yuan,Fang, Shiyue
p. 1750 - 1757
(2018/08/21)

Method for synthesizing aminopyridine and 4-aminopyridine in one step
The invention discloses a method for synthesizing aminopyridine and 4-aminopyridine in one step and belongs to the technical field of chemical material synthesis. The method comprises the following steps: in a low temperature condition, carrying out a pre-reaction in a sodium hypochlorite aqueous solution by taking cyanopyridine as a raw material and sodium tungstate as a catalyst (the adding amount of the catalyst is about 2-5% by mass of the raw material cyanopyridine), wherein the reaction is stopped on formamide pyridine; and then raising the temperature for Hoffman one-step reaction to obtain aminopyridine. Taking synthesis of 4-aminopyridine as an example, the reaction condition is easy to control, the reaction step is simple, the product is convenient to operate, side reactions arefew, the product purity can reach 99.95%, and problems of severe pollution, low yield and the like in the prior art are solved.
-
Paragraph 0033-0038; 0043; 0044-0050; 0055-0060

(2018/12/13)

Application of Silicon-Initiated Water Splitting for the Reduction of Organic Substrates
The use of water as a donor for hydrogen suitable for the reduction of several important classes of organic compounds is described. It is found that the reductive water splitting can be promoted by several metalloids among which silicon shows the best efficiency. The developed methodologies were applied for the reduction of nitro compounds, N-oxides, sulfoxides, alkenes, alkynes, hydrodehalogenation as well as for the gram-scale synthesis of several substrates of industrial importance.
Gevorgyan, Ashot,Mkrtchyan, Satenik,Grigoryan, Tatevik,Iaroshenko, Viktor O.
p. 375 - 382
(2018/06/04)

Copper-mediated reduction of azides under seemingly oxidising conditions: Catalytic and computational studies
The reduction of aryl azides in the absence of an obvious reducing agent is reported. Careful catalyst design led to the production of anilines in the presence of water and air. The reaction medium (toluene/water) is crucial for the success of the reaction, as DFT calculations support the formation of benzyl alcohol as the oxidation product. A singular catalytic cycle is presented for this transformation based on four key steps: nitrene formation through nitrogen extrusion, formal oxidative addition of water, C(sp3)-H activation of toluene and reductive elimination.
Zelenay, Benjamin,Besora, Maria,Monasterio, Zaira,Ventura-Espinosa, David,White, Andrew J. P.,Maseras, Feliu,Díez-González, Silvia
p. 5763 - 5773
(2018/11/24)

Method for preparing aminopyridine from methylpyridine, and purifying method of aminopyridine
The invention relates to the field of organic synthesis, and concretely relates to a method for preparing aminopyridine from methylpyridine, and a purifying method of aminopyridine. Crude aminopyridine is prepared from corresponding methylpyridine through oxidation, esterification, hydrazinolysis and rearrangement reactions, the reaction yield of every step is high, and a post-treatment technology is easy to industrially operate; in the oxidation reaction, beta-cyclodextrin is used as a catalyst, so the conversion rate of the oxidation reaction is increased, and the generation of byproducts is reduced; and anhydrous ethanol and an alkane reagent are used to re-crystallize the crude aminopyridine, and a decolorizing agent is combined, and the purity of the final product reaches 98% or more; and the purifying method has the advantages of simplicity, easiness in operation, easily available raw materials, and suitableness for industrial production.
-
(2017/09/01)

Highly chemoselective reduction of azides to amines by Fe(0) nanoparticles in water at room temperature
A highly chemoselective reduction of aryl, heteroaryl, acyl and sulfonyl azides to the corresponding amines has been achieved by Fe(0) nanoparticles in water at room temperature in the absence of external hydride source. Several readily reducible functionalities including alkene, alkyne, S-S linkage, OTBDMS remain unaffected during reduction.
Panja, Subir,kundu, Debasish,Ahammed, Sabir,Ranu, Brindaban C.
supporting information
p. 3457 - 3460
(2017/08/10)

Preparation method of reaches the side pyridine (by machine translation)
The invention relates to a method for preparing reaches the side pyridine, comprises the following steps: 1) the amino resin and isonicotinic acid coupling agent of preparing nicotinic acid amide resin; 2) the lysate to get rid of the resin, of preparing nicotinic acid amide; 3) step 2) the resulting different nicotinic acid amide by degrading reagent and alkali, obtained by Hofmann degradation reaches the side pyridine. (by machine translation)
-
Paragraph 0039; 0040; 0041; 0042; 0043; 0044; 0045

(2017/08/28)

One-pot synthesis of primary amines from carboxylic acids through rearrangement of in situ generated hydroxamic acid derivatives
A one-pot synthesis of primary amines from carboxylic acids through a Lossen rearrangement of hydroxamic acid derivatives, which were in situ generated by the reaction of carboxylic acids with O-trimethylsilylhydroxylamine (NH2OTMS) and carbonyl diimidazole (CDI, 1.5 equiv) in dimethyl sulfoxide at room temperature, has been achieved. This one-pot method could be applied to various carboxylic acids such as aromatic, heteroaromatic, aliphatic, and optically active substrates.
Hoshino, Yujiro,Ohtsuka, Naoya,Okada, Takuya,Honda, Kiyoshi
p. 5304 - 5307
(2016/11/16)

Method for synthesizing 4-aminopyridine
The invention discloses a method for synthesizing 4-aminopyridine. The method comprises the following steps: carrying out a reaction on 4-chloropyridine used as an initial raw material and liquefied ammonia under the action of a catalyst under 0.8-3.0 MPa at 30-90 DEG C for 4-15 h, removing ammonia, washing the above obtained reaction product with water, filtering the washed product, and drying the filtered product to obtain the target product 4-aminopyridine. The catalyst is one of iron chloride, zinc chloride and copper chloride, and the use amount of the catalyst is 1-10% of the use amount of 4-chloropyridine. The method for synthesizing 4-aminopyridine from the cheap raw material 4-chloropyridine has the advantages of high yield, and realization of very low requirements of devices and safety due to the low reaction temperature, and is suitable for industrial production and application.
-
Paragraph 0017-0018

(2017/05/26)

A practical and highly efficient reductive dehalogenation of aryl halides using heterogeneous Pd/AlO(OH) nanoparticles and sodium borohydride
The reductive dehalogenation of aryl halides was performed by using commercially available aluminium oxy-hydroxide-supported palladium (Pd/AlO(OH)) nanoparticles of about 3?nm size (0.5?wt.?% Pd) with sodium borohydride. The dehalogenated products were obtained with absolute conversion in a mixture of H2O/MeOH (v/v=1/1) under ultrasonic conditions at room temperature. All aryl halides were successfully converted to halogen-free compounds within 1.5–4?h with yields of over 95%. The one-pot catalytic method is presented as a new process for the reductive dehalogenation of halogenated compounds. This method is quite simple, highly efficient and eco-friendly, and has an exceptional recovery rate.
Kara, Belguzar Yasemin,Yazici, Melike,Kilbas, Benan,Goksu, Haydar
p. 5898 - 5902
(2016/09/07)

A Metal and Base-Free Chemoselective Primary Amination of Boronic Acids Using Cyanamidyl/Arylcyanamidyl Radical as Aminating Species: Synthesis and Mechanistic Studies by Density Functional Theory
An efficient, metal and base-free, chemoselective synthesis of aryl-, heteroaryl-, and alkyl primary amines from the corresponding boronic acids has been achieved at ambient temperature mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA) and N-bromosuccinimide (NBS) using cyanamidyl/arylcyanamidyl radicals as the aminating species. The primary amine compounds were initially obtained as their corresponding ammonium trifluoroacetate salts which, on treatment with aq NaOH, provide the free amines. Finally, the primary amines were isolated through column chromatography over silica-gel using hexane-EtOAc solvent system as the eluent. The reactions are sufficiently fast, completing within 1 h. Quantum chemical calculations in combination with experimental observations validate that the ipso amination of substituted boronic acids involves the formation of cyanamidyl/arylcyanamidyl radical, followed by regiospecific interaction of its nitrile-N center with boron atom of the boronic acids, leading to chemoselective primary amination.
Chatterjee, Nachiketa,Arfeen, Minhajul,Bharatam, Prasad V.,Goswami, Avijit
p. 5120 - 5127
(2016/07/06)

Stable and reusable platinum nanocatalyst: An efficient chemoselective reduction of nitroarenes in water
Binaphthyl stabilized Pt nanoparticles (Pt-BNP) have been synthesized, characterized, and utilized as an efficient heterogeneous catalyst for chemoselective reduction of nitroarenes at room temperature in water. Several sensitive functional groups like ketone, ester, acid, amide, halides, and nitrile were well tolerated in this chemoselective reduction. The Pt-BNP catalyst was quantitatively recovered without any major change in particle size and reactivity and then efficiently reused for five catalytic cycles.
Kotha, Surya Srinivas,Sharma, Nidhi,Sekar, Govindasamy
supporting information
p. 1410 - 1413
(2016/03/12)

Five-And-Six-Membered Heterocyclic Compound, And Preparation Method, Pharmaceutical Composition And Use Thereof
A five-and-six-membered heterocyclic compound as represented by general formula I, pharmaceutically acceptable salt, metabolite, metabolic precursors or drug precursors thereof, preparation method, pharmaceutical composition, and use thereof; the five-and-six-membered heterocyclic compound has activity as a Janus kinase (JAK) inhibitor, and can be used to prepare drugs for treating diseases caused by the abnormal activity of kinase, such as cell proliferation diseases like cancer.
-
Paragraph 0210; 0211

(2015/12/07)

Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA)
A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.
Chatterjee, Nachiketa,Goswami, Avijit
supporting information
p. 7940 - 7945
(2015/07/27)

Peptide deformylase inhibitors
The present invention relates to a compound of Formula (I): or a pharmaceutically acceptable salt thereof, corresponding pharmaceutical compositions, compound preparation and treatment methods directed to bacterial infections and inhibition of bacterial peptide deformylase (PDF) activity.
-
Page/Page column

(2014/12/09)

Polymethylhydrosiloxane derived palladium nanoparticles for chemo- and regioselective hydrogenation of aliphatic and aromatic nitro compounds in water
Chemo- and regioselective hydrogenation of a wide range of aliphatic, unsaturated, aromatic and heteroaromatic nitro compounds into their corresponding amines has been achieved with highly efficient polysiloxane-stabilised "Pd" nanoparticles on NAP-magnesium oxide supports using an environmentally friendly hydrogenating agent, polymethylhydrosiloxane [PMHS] in water. Highly stable and active Pd nanoparticles were prepared by the reduction of NAP-Mg-PdCl4 with PMHS, which serves as a reducing agent as well as a capping agent. The well-dispersed palladium nanoparticles on NAP-MgO catalysts also exhibit excellent regioselectivity in the hydrogenation of dinitrobenzenes to the corresponding nitroanilines. The catalyst has high durability against sintering during the hydrogenation reaction and can be reused with no loss in its activity. This journal is the Partner Organisations 2014.
Damodara, Dandu,Arundhathi, Racha,Ramesh Babu, T. Venkata,Legan, Margaret K.,Kumpaty, Hephzibah J.,Likhar, Pravin R.
p. 22567 - 22574
(2014/06/23)

PEPTIDE DEFORMYLASE INHIBITORS
The present invention relates to a compound of Formula (I): or a pharmaceutically acceptable salt thereof, corresponding pharmaceutical compositions, compound preparation and treatment methods directed to bacterial infections and inhi-bition of bacterial peptide deformylase (PDF) activity
-
Page/Page column

(2014/02/15)

Copper(I)-catalyzed amination of aryl halides in liquid ammonia
The amination of aryl halides in liquid ammonia (LNH3) is catalyzed by a copper(I) salt/ascorbate system to yield primary aromatic amines in good to excellent yields. The low concentrations of catalyst required and the ease of product isolation suggest that this process has potential industrial applications. Commonly used ligands for analogous metal-catalyzed reactions are not effective. The rate of amination of iodobenzene in liquid ammonia is first order in copper(I) catalyst concentration. The small Hammett I? = 0.49 for the amination of 4-substituted iodobenzenes in liquid ammonia at 25 °C indicates that the C-I bond is not significantly broken in the transition state structure and that there is a small generation of negative charge in the aryl ring, which is compatible with the oxidative addition of the copper ion being rate limiting.
Ji, Pengju,Atherton, John H.,Page, Michael I.
p. 7471 - 7478
(2012/11/06)

AN IMPROVED PROCESS FOR PRODUCING AMINOPYRIDINES
Disclosed herein is an improved process for producing aminopyridine compounds analogs, substituted forms, derivatives, or the pharmaceutically acceptable salts, esters, amides and prodrugs thereof with high purity and yield at industrial scale.
-
Page/Page column 9

(2012/07/28)

PROCESS FOR THE PREPARATION OF FAMPRIDINE
The present invention relates to a process for the preparation of substantially pure fampridine compound of structural formula (I), (II), (III) comprising nitrifying pyridine-N-oxide hydrochloride with suitable nitrating agent; reducing with suitable reducing agent and purifying by recrystallizing in water followed by treating with an alkyl acetate solvent.
-
Page/Page column 13-14

(2011/10/03)

One-pot process for the synthesis of dalfampridine
A process for the preparation of Dalfampridine (1), 4-aminopyridine, starting from 4-pyridinecarbonitrile using a one-pot procedure. Said process is carried out with no need for isolating intermediates and is particularly advantageous as far as environment, yields, productivity and purity of the resulting product are concerned, both in the reaction mixture and in the isolated crystal.
-
Page/Page column 7-8

(2012/01/03)

ONE-POT PROCESS FOR THE SYNTHESIS OF DALFAMPRIDINE
A process for the preparation of Dalfampridine (1), 4-aminopyridine, starting from 4-pyridinecarbonitrile using a one-pot procedure. Said process is carried out with no need for isolating intermediates and is particularly advantageous as far as environment, yields, productivity and purity of the resulting product are concerned, both in the reaction mixture and in the isolated crystal.
-
Page/Page column 4-5

(2012/01/13)

Selective photocatalytic reductions of nitrobenzene derivatives using PbBiO2X and blue light
Blue light irradiation of heterogeneous photocatalysts PbBiO2X (X = Cl, Br) in the presence of triethanolamine as an electron donor leads to hydrogen evolution, and the selective, clean and complete reduction of nitrobenzene derivatives to their corresponding anilines. The Royal Society of Chemistry.
Fueldner, Stefan,Pohla, Patrick,Bartling, Hanna,Dankesreiter, Stephan,Stadler, Roland,Gruber, Michael,Pfitzner, Arno,Koenig, Burkhard
supporting information; experimental part
p. 640 - 643
(2011/05/04)

Rapid reduction of heteroaromatic nitro groups using catalytic transfer hydrogenation with microwave heating
A method for the rapid, safe reduction of heteroaromatic and aromatic nitro groups to amines is described using catalytic transfer hydrogenation under microwave heating conditions. Commonly available Pd/C or Pt/C catalyst is extremely effective with 1,4-cyclohexadiene as the hydrogen transfer source. In the case of substrates containing potentially labile aromatic halogens, Pt/C is effective and results in little or no dehalogenation. In general, the reactions are complete within 5 min at 120 °C.
Quinn, John F.,Bryant, Cole E.,Golden, Kathryn C.,Gregg, Brian T.
experimental part
p. 786 - 789
(2010/03/24)

PHOTOLABILE COMPOUNDS
The present invention describes Photolabile Compounds methods for use of the compounds. The Photolabile Compounds have a photoreleasable ligand, which can be biologically active, and which is photoreleased from the compound upon exposure to light. In some embodiments, the Photolabile Compounds comprise a light antenna, such as a labeling molecule or an active derivative thereof. In one embodiment, the light is visible light, which is not detrimental to the viability of biological samples, such as cells and tissues, in which the released organic molecule is bioactive and can have a therapeutic effect. In another embodiment, the photoreleasable ligand can be a labeling molecule, such as a fluorescent molecule.
-
Page/Page column 59-60

(2011/01/12)

A simple synthesis of aminopyridines: Use of amides as amine source
A transition metal/microwave irradiation (or base) free synthesis of aminopyridines has been accomplished via C-N bond forming reaction between chloropyridine and a variety of simple amides under refuxing conditions.
Kodimuthali, Arumugam,Mungara, Anitha,Prasunamba, Padala Lakshmi,Pal, Manojit
experimental part
p. 1439 - 1445
(2010/11/04)

Efficient copper-catalyzed coupling of aryl chlorides, bromides and iodides with aqueous ammonia
The copper(i)-catalyzed synthesis of a range of primary anilines from electron-rich and electron-deficient aryl halides including aryl chlorides has been achieved with aqueous ammonia, avoiding the need for inert atmosphere, expensive catalysts and ligands, anhydrous solvents, and additional base or other additives. The Royal Society of Chemistry 2009.
Xu, Hanhui,Wolf, Christian
supporting information; experimental part
p. 3035 - 3037
(2009/12/01)

The effect of substitution on the utility of piperidines and octahydroindoles for reversible hydrogen storage
Substituted piperidines and octahydroindoles are compared in terms of their usability as reversible organic hydrogen storage liquids for hydrogen-powered fuel cells. Theoretical Gaussian calculations indicate which structural features are likely to lower the enthalpy of dehydrogenation. Experimental results show that attaching electron donating or conjugated substituents to the piperidine ring greatly increases the rate of catalytic dehydrogenation, with the greatest rates being observed with 4-aminopiperidine and piperidine-4-carboxamide. Undesired side reactions were observed with some compounds such as alkyl transfer reactions during the dehydrogenation of 4-dimethylaminopiperidine, C-O and C-N cleavage reactions during hydrogenation and/or subsequent dehydrogenation of 4-alkoxy and 4-amino indoles, and disproportionation during the hydrogenation of 4-aminopyridine. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Cui, Yi,Kwok, Samantha,Bucholtz, Andrew,Davis, Boyd,Whitney, Ralph A.,Jessop, Philip G.
p. 1027 - 1037
(2008/12/20)

Photolabile Compounds
The present invention describes Photolabile Compounds methods for use of the compounds. The Photolabile Compounds have a photoreleasable ligand, which can be biologically active, and which is photoreleased from the compound upon exposure to light. In one embodiment, the light is visible light, which is not detrimental to the viability of biological samples, such as cells and tissues, in which the released organic molecule is bioactive and can have a therapeutic effect.
-
Page/Page column 15; 5/12

(2008/12/07)

Displacement of neutral nitrogen donors by chloride in AuCl3(am) (am = pyridines and amines): Kinetics and DFT calculations show the effects of basicity and π-acceptor ability
The kinetics of the process AuCl3(am) + Cl- → AuCl4- + am (am = sp2 N-donor isosteric pyridines with different π systems and sp3 amines; they cover a wide range of basicity) have been studied in methanol at 25°C. The reactions obey the usual two-term rate law observed in substitutions on square-planar complexes. The second-order rate constants, k2, are very sensitive to the nature of the leaving group, and plots of log k2 against the pKa of the conjugate acids are linear, with the same slope, -0.68, for both normal pyridines and pyridines with a more extended π system, such as 4-cyanopyridine, isonicotinic acid, methyl isonicotinate and 4-acetylpyridine. The reactivity of the considered N-donors is different and follows the order sp3 N-donors > normal pyridines > π-extended pyridines. This result, with the support of ground-state DFT calculations on the AuCl3(am) derivatives, is explained on the basis of an Au-N bond enforcement due to an increased π-back-donation contribution. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Pitteri, Bruno,Bortoluzzi, Marco
p. 4456 - 4461
(2008/03/12)

Synthesis, spectral, thermal and kinetic studies on the adducts with pyridines of tungsten(V) binuclear thiocomplexes with di-isopropyl-dithiocarbamate
We report the synthesis and the thermal and kinetic behaviour of di-μ-sulfido-bis-(sulfido N,N,di-i-propyldithiocarbamate)di-tungsten(V) adducts with pyridine or substituted pyridines, the formula of which is [W2S4(di-i-propyldtc)2B2], where dtc = dithiocarbamate and B = pyridine (Py), 3-methylpyridine (3-MP), 4-methylpyridine (4-MP), 3,5-dimethylpyridine (3,5-DMP), 3-aminopyridine (3-AP) and 4-aminopyridine (4-AP). The synthesized complexes have been identified by IR and electronic spectra, magnetic susceptibility measurements and analytical data. We have also inferred the thermal behaviour and kinetic parameters by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of the thermal decomposition of these adducts in the solid state. From the DSC curves, the activation energies and pre-exponential Arrhenius factors for the endothermic process corresponding to the loss of two moles of coordinated base were calculated. We have also deduced the reaction mechanism using a new non-isothermal kinetic method. Steric hindrance and inductive effects prompted by amino and methyl pyridine functional groups in the adducts formation are discussed. A relationship between the pyridines basicity, infrared and electronic spectral data and activation energies has also been explored.
Lozano,de Jesús,Lozano
p. 3127 - 3132
(2008/10/09)

Amides, useful in the inhibition of il-8-induced chemotaxis of neutrophils
N-(2-aryl-propionyl)-amides of formula (I) are described. The process for their preparation and pharmaceutical preparations thereof are also described. The amides of the invention are useful in the prevention and treatment of tissue damage due to the exacerbate recruitment of polymorphonuclear neutrophils (leukocytes PMN) at the inflammatory sites. In particular, the invention relates to the R enantiomers of N-(2-aryl-propionyl)amides of formula (I) for use in the ihibition of the chemotaxis of neutrophils induced by IL-8. The compounds of the invention are used in the treatment of psoriasis, ulcerative cholitis, glomerular nephritis, acute respiratory insufficiency, idiopathic fibrosis, and rheumatoid arthritis.
-
(2008/06/13)

Conventional and microwave assisted hydrogenolysis using zinc and ammonium formate
The selective deprotection of several N-Bzl amino derivatives to the corresponding amines and the removal of S-Bzl and O-Bzl groups from the protected amino acids with ammonium formate and commercial zinc dust are reported. Many other reducible or hydrogenolysable substituents such as halogens, methoxy, phenol, ester, acid, ethene, and Boc groups are unaffected.
Srinivasa,Babu, S. N. Narendra,Lakshmi,Gowda, D. Channe
p. 1831 - 1837
(2007/10/03)

The hydrogenolysis of N-benzyl groups with a magnesium and ammonium formate
The selective deprotection of several N-Bn amino derivatives to the corresponding amines and the removal of S-Bn and O-Bn groups from the protected amino acids with ammonium formate and magnesium is reported.
Babu, S.N. Narendra,Srinivasa,Santhosh,Gowda, D. Channe
p. 66 - 67
(2007/10/03)

An Efficient Deoxgenation of Heteroaromatic N-Oxides Using Zinc Dust/Ammonium Formate Reagent System
Heteroaromatic N-oxides were readily and selectively deoxygenated to the corresponding bases with zinc/ammonium formate reagent system.
Balicki, Roman,Cybulski, Marcin,Maciejewski, Grzegorz
p. 4137 - 4141
(2007/10/03)

SUBSTITUTED QUINAZOLINE DERIVATIVES AND THEIR USE AS INHIBITORS
The use of a compound of formula (I) 1 or a salt, ester or amide thereof; where X is O, or S, S(O) or S(O)2, or NR6 where R6 is hydrogen or C1-6 alkyl,; R5 is an optionally substituted 5-membered heteroaromatic ring, R1, R2 ,R3, R4 are independently selected from various specified moieties, in the preparation of a medicament for use in the inhibition of aurora 2 kinase. Certain compounds are novel and these, together with pharmaceutical compositions containing them are also described and claimed
-
(2008/06/13)

PROCESS FOR CONVERTING HYDROXY HETEROAROMATICS TO ARYLAMINES
A process of converting a hydroxy heteroaromatic compound to an arylamine, comprising the steps of : 1) treating a salt of a hydroxy heteroaromatic compound with an alkylating agent; and 2) treating the reaction mixture with a Smiles solvent system and raising the temperature of the reaction mixture; and a compound made according to the above process.
-
(2008/06/13)

A mild and selective deoxygenation of N-oxides with ammonium formate as a catalytic hydrogen transfer agent
Ammonium formate catalytic transfer hydrogenation in the presence of raney nickel has shown utility for mild and selective deoxygenation of heteroaromatic N-oxides in neutral medium.
Balicki, Roman,Maciejewski, Grzegorz
p. 1681 - 1683
(2007/10/03)

Reductive amination of quinoline N-oxide with aminopyridines and their N-tozyl derivatives
In reaction of quinoline N-oxide with 2-aminopyridine in the presence of tosyl chloride the substrate undergoes reductive amination into 2-pyridyl(2-quinolyl)amine, and with 3- and 4-aminopyridines reductive tosylamination occurs to furnish N-tosyl derivatives of the corresponding 3- and 4-pyridyl(2-quinolyl)amines. N-tosyl derivatives of aminopyridines also react along reductive tosylamination pathway.
Solekhova,Kurbatov
p. 1192 - 1194
(2007/10/03)

CRF receptor antagonists and methods relating thereto
CRF receptor antagonists are disclosed which have utility in the treatment of a variety of disorders, including the treatment of disorders manifesting hypersecretion of CRF in a warm-blooded animals, such as stroke. The CRF receptor antagonists of this invention have the following structure: including stereoisomers, prodrugs and pharmaceutically acceptable salts thereof, wherein m, R, R1, R2, A, X, Y and Z are as defined herein. Compositions containing a CRF receptor antagonist in combination with a pharmaceutically acceptable carrier are also disclosed, as well as methods for use of the same.
-
(2008/06/13)