- Electronic properties and ultraviolet absorption and fluorescence spectra of 2,6-pyridinediamine
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The u.v. absorption and fluorescence spectra of 2,6-pyridinediamine and its carboxylate salts were measured in various solvents at room teemperature and 77K.These spectral data were interpreted by molecular orbital method.From these results it was found that the formation of 6-amino-2(H)-pyridinimine through the 2,6-pyridinediamine hydrogen bonded compex with ethanol occurs only in the ?,?* excited singlet state in the ethanol and isooctane mixed solvent.On the other hand, the fluorescence spectrum of 2,6-pyridinediamine in the pH > 13 controlled solution was assigned to the monoanion species, that is, the 6-amino-2-pyridylamide ion which was formed in the first ?,?* excited singlet state.
- Fujimoto, Akira,Inuzuka, Kozo
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- Hydrogen-bonded complexes of diaminopyridines and diaminotriazines: Opposite effect of acylation on complex stabilities
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The association behavior of several 2,4-diamino-s-triazines, 2,6-diaminopyridines, and their acylated derivatives with uracil derivatives was studied. In solution 1H-NMR and IR spectroscopy were used, and in the solid state as (co)crystals X-ray diffraction was used. Acylation of 2,6-diaminopyridine leads to an increase of the association constant in CDCl3 of the complexes with N-propylthymine from 84 to 440-920 M-1, whereas acylation of diamino-s-triazines leads to a dramatic fall in the association constant of the complexes with N-propylthymine from 890 to ca. 6 M-1. This phenomenon is related to different conformational preferences of these compounds. The amide groups in bis(acylamino)pyridines prefer a trans conformation, with the carbonyl group anti with respect to the ring nitrogen and coplanar with the aromatic ring. The amides of bis(acylamino)triazines, however, reside predominantly in a cis conformation. Repulsive secondary electrostatic interactions between the cis-amide and uracil carbonyl groups are thought to be responsible for the low association constant of complexes of bis(acylamino)triazines with uracils. The relatively high dimerization constants of bis(acylamino)triazines have been rationalized by the strong tendency to dimerize via quadruple hydrogen bonding.
- Beijer, Felix H.,Sijbesma, Rint P.,Vekemans, Jef A. J. M.,Meijer,Kooijman, Huub,Spek, Anthony L.
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- ZnFe-LDH/GO nanocomposite coated on the glass support as a highly efficient catalyst for visible light photodegradation of an emerging pollutant
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This study reports the fabrication of ZnFe-layered double hydroxides with sulfate-intercalated anion (ZnFe-SO4-LDH) modified with graphene oxide (GO) by chemical co-precipitation method. They were then coated on the glass substrates (denoted as ZnFe-LDH/GO/GS). The XRD, SEM, EDX, X-ray Dot-mapping, FTIR, AFM, UV–Vis DRS, and PL analyses were used for the characterization of the as-synthesized sample. The photocatalytic implementation of the as-prepared photocatalyst was scrutinized for the degradation of phenazopyridine hydrochloride (PhP) from the solution under visible light irradiation. The prepared photocatalyst showed photocatalytic performance of elimination PhP, the degraded rate of pollutant could reach 60.01% in 150 min of photocatalysis process under the optimum conditions: initial PhP concentration of 15 mg/L, pH of 8 (natural pH), and 3 photocatalysts plates. The addition of 1 mmol/L of potassium persulfate (k2S2O8) caused the degradation efficiency of 93.95% within the 150 min of photocatalytic process. Trapping experiments indicated the influence order of O2 ?· > [rad]OH > h+ for the ROSs present in decomposition. The transformation of five intermediates of PhP produced in the photocatalytic degradation process was identified by the GC–MS technique. 60% COD removal efficiency was achieved after 300 min of photocatalytic reaction confirming mineralization of the PhP solution. Finally, a reusability test of ZnFe-LDH/GO/GS photocatalyst in the PhP degradation revealed that almost 12% drop occurred after five successive cycles.
- Motlagh, Parisa Yekan,Khataee, Alireza,Hassani, Aydin,Sadeghi Rad, Tannaz
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- Nitration method for preparing 2, 6-diamido-3, 5-binitro pyridine by ultrafine zeolite-based micro-channel reaction
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The invention provides a nitration method for preparing 2, 6-diamido-3, 5-binitro pyridine by ultrafine zeolite-based micro-channel reaction. The nitration method includes the steps: heating and uniformly mixing crushed sodium amide, decahydronaphthalene and p-toluidine, performing microwave heating reaction on mixture and pyridine by a Y-shaped micro-channel reactor, and filtering and recrystallizing the mixture and the pyridine to obtain 2, 6-diamido pyridine; blowing ultrafine HZSM-5 catalysts into an outlet channel of the Y-shaped micro-channel reactor, placing the modified Y-shaped micro-channel reactor into an ice-water bath, leading the 2, 6-diamido pyridine and dichloromethane solution containing nitrogen pentoxide into the Y-shaped micro-channel reactor, accelerating flow and rapidly increasing temperature to reach reaction temperature to obtain a 2, 6-diamido-3, 5-binitro pyridine crude product; secondarily recrystallizing, filtering and drying the 2, 6-diamido-3, 5-binitro pyridine crude product, adding the crude product into distilled water, boiling the distilled water and performing dimethyl sulfoxide secondary crystallization to obtain the 2, 6-diamido-3, 5-binitro pyridine with high yield and purity.
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(2019/03/08)
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- Diamination of phenylene dihalides catalyzed by a dicopper complex
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Diamination of phenylene dihalides with aqueous ammonia to give the corresponding phenylenediamines can be achieved by using a dicopper complex [Cu2(bpnp)(OH)(CF3COO)3] (1) (bpnp = 2,7-bis(pyridine-2-yl)-l,8-naphthyridine) as the catalyst in the presence of Bu4NBr and Cs2CO3 in high yields. In addition, 1,3,5-tribromobenzene was converted into benzenetriamine quantitatively under the same conditions. This method offers a new opportunity, particularly simplifying steps and increasing yields, for the preparation of aryl diamines.
- Liao, Bei-Sih,Liu, Shiuh-Tzung
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experimental part
p. 6653 - 6656
(2012/10/07)
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- Efficient synthesis of aminopyridine derivatives by copper catalyzed amination reactions
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A copper(i) catalyzed amination reaction utilizing aqueous ammonia and operating under mild conditions is presented. This method was employed for the efficient synthesis of various aminopyridine derivatives bearing electron withdrawing and electron donating groups. The Royal Society of Chemistry 2010.
- Elmkaddem, Mohammed K.,Fischmeister, Cedric,Thomas, Christophe M.,Renaud, Jean-Luc
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supporting information; experimental part
p. 925 - 927
(2010/06/12)
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- PROCESS FOR THE SYNTHESIS OF DIAMINOPYRIDINES FROM GLUTARONITRILES
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A liquid-phase process is provided for the manufacture from glutaronitriles and related compounds of 2,6-diaminopyridine and related compounds, which are used industrially as compounds and as components in the synthesis of a variety of useful materials. The synthesis proceeds by means of a dehydrogenative aromatization process.
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(2010/03/02)
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- GAS-PHASE PROCESS FOR THE SYNTHESIS OF DIAMINOPYRIDINES FROM GLUTARONITRILES
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A gas-phase, continuous process is provided for the manufacture of 2,6-diaminopyridine and related compounds from glutaronitriles, which are used industrially as compounds and as components in the synthesis of a variety of useful materials. The synthesis proceeds by means of a dehydrogenative aromatization process.
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(2010/02/17)
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- CONTINUOUS LIQUID-PHASE PROCESS FOR THE SYNTHESIS OF DIAMINOPYRIDINES FROM GLUTARONITRILES
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A liquid-phase, continuous process is provided for the manufacture of 2,6-diaminopyridine and related compounds from glutaronitriles, which are used industrially as compounds and as components in the synthesis of a variety of useful materials. The synthesis proceeds by means of a dehydrogenative aromatization process.
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(2010/08/04)
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- PROCESS FOR THE SYNTHESIS OF DIAMINOPYRIDINE AND RELATED COMPOUNDS
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A process is provided for the synthesis of a diaminopyridine, such as 2,6-diaminopyridine and related compounds, which are used industrially as compounds and as components in the synthesis of a variety of useful materials. The synthesis proceeds by means of a chlorine-ammonia displacement in the presence of a copper source.
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- PROCESS FOR THE SYNTHESIS OF DIAMINOPYRIDINE AND RELATED COMPOUNDS
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A process is provided for the synthesis of a diaminopyridine, such as 2, 6-diaminopyridine and related compounds, which are used industrially as compounds and as components in the synthesis of a variety of useful materials. The synthesis proceeds by means of a chlorine-ammonia displacement in the presence of a copper source.
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- PROCESS FOR THE SYNTHESIS OF DIAMINOPYRIDINES FROM GLUTARIMIDINES
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A liquid-phase process is provided for the synthesis from glutarimidines of diaminopyridines and related compounds, which are used industrially as compounds and as components in the synthesis of a variety of useful materials. The synthesis proceeds by means of a dehydrogenative aromatization process.
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- Hydroformylation
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The present invention relates to a process for hydroformylating in the presence of a catalyst comprising at least one complex of a metal of transition group VIII with mono-phosphorus compounds which are capable of dimerizing via noncovalent bonds as ligands, to such catalysts and to their use.
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- Composition of matter having bioactive properties
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Particles of coordinated complex comprising a basic, hydrous polymer and a capacitance adding compound, as well as methods for their production, are described. These complexes exhibit a high degree of bioactivity making them suitable for a broad range of applications through their incorporation into conventional vehicles benefiting from antimicrobial and similar properties.
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- THERMAL REARRANGEMENTS OF 2,6-DI(PYRIDYLMETHYLENEAMINO)PYRIDINES INTO 3,5-DIPYRIDYLMETHYLENE-2,6-DIAMINOPYRIDINES
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Novel results obtained during thermal rearrangement studies on N,N'-dipyridylmethylene-2,6-diaminopyridines are reported.Formation of derivatives with pyridylmethylene groups at positions 3 and 5, together with N-pyridylmethylene-2,6-diaminopyridynes in reaction of 2,6-diaminopyridine with 2- or 4-pyridylmethanols has been staded.
- Kowalski, Piotr,Czuba, Wladyslaw
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p. 1184 - 1190
(2007/10/02)
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- Ethylenic silicon compounds and thermoplastic elastomers obtained therefrom
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The invention provides organosilicon compounds of the formula: STR1 in which: N IS 1, 2 OR 3; Each R, which may be identical or different, is a monovalent organic group which contains a carbon-carbon double bond and from 2 to 10 carbon atoms; Each R1, which may be identical or different, is a straight or branched alkyl radical optionally substituted by one or more halogen atoms or cyano groups; an aryl radical or an alkylaryl radical optionally substituted by one or more halogen atoms; R2 is a straight or branched divalent alkylene or alkylidene radical possessing up to 4 carbon atoms; X is a divalent radical consisting of, or containing, at least one hetero-atom selected from oxygen, sulphur and nitrogen atoms, the radical being attached to the radical R2 via a said hetero-atom; G is an organic radical of valency (m+ l) possess from 1 to 30 carbon atoms; m is 1, 2 or 3; And each Y, which may be identical or different, is a functional group selected from: --NO2, STR2 --COOM (where M represents a sodium, potassium or lithium atom); --COOR4 ; STR3 --COCl; --OH; --OR4 ; STR4 --SH; --SR4 ; STR5 --CONH2 ; --CSNH2 ; --CN; --CH2 --NH2 ; --CHO; STR6 --NCO; STR7 wherein R3 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 6 carbon atoms and R4 represents an alkyl radical possessing up to 4 carbon atoms, with the proviso that two Y groups can together constitute an imide group STR8 wherein R5 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 4 carbon atoms. These are useful intermediates in the preparation of disilanes and silicon polymers, in particular of polyethylenic silicon compounds which can be polymerized with an α, ω-dihydrogenopolysiloxane to give thermoplastic elastomers.
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