Showing papers on "Triazene published in 2016"
TL;DR: Molecular, isolated N3 H3 is observed in the gas phase after it sublimes from energetically processed ammonia and nitrogen films using a novel detection scheme of photoionization-driven reflectron time-of-flight mass spectroscopy and isotopically labeled starting material.
Abstract: The remarkable versatility of triazenes in synthesis, polymer chemistry and pharmacology has led to numerous experimental and theoretical studies. Surprisingly, only very little is known about the most fundamental triazene: the parent molecule with the chemical formula N3 H3 . Here we observe molecular, isolated N3 H3 in the gas phase after it sublimes from energetically processed ammonia and nitrogen films. Combining theoretical studies with our novel detection scheme of photoionization-driven reflectron time-of-flight mass spectroscopy we can obtain information on the isomers of triazene formed in the films. Using isotopically labeled starting material, we can additionally gain insight in the formation pathways of the isomers of N3 H3 under investigation and identify the isomers formed as triazene (H2 NNNH) and possibly triimide (HNHNNH).
21 citations
TL;DR: In this paper, a Rh(III)-catalyzed aromatic C-H bond carbenoid functionalization of triazenes by α-diazomalonates has been developed, with features of mild reaction condition and high efficiency.
16 citations
TL;DR: A novel strategy for regioselective cross-dehydrogenative couplings of two different C-H bonds is provided and α-carbon configuration of some amino acid residues in the substrates was kept after the reactions, and the couplings for substrates with substituted phenylalanine residues exhibited complete β-carbon diastereoselectivity for induction of the chiral α- carbon.
Abstract: Cross-dehydrogenative couplings of two different C-H bonds have emerged as an attractive goal in organic synthesis. However, achieving regioselective C-H activation is a great challenge because C-H bonds are ubiquitous in organic compounds. Actually, the regioselective couplings promoted by enzymes are a common occurrence in nature. Herein, we have developed simple, efficient and general transition metal-free intramolecular couplings of alphatic and aromatic C-H bonds. The protocol uses readily available aryl triazene as the radical initiator, cheap K2S2O8 as the oxidant, and the couplings were performed well with excellent tolerance of functional groups. Interestingly, α-carbon configuration of some amino acid residues in the substrates was kept after the reactions, and the couplings for substrates with substituted phenylalanine residues exhibited complete β-carbon diastereoselectivity for induction of the chiral α-carbon. Therefore, the present study should provide a novel strategy for regioselective cross-dehydrogenative couplings of two different C-H bonds.
13 citations
TL;DR: In this article, a modified graphene oxide (GO) was prepared as a solid adsorbent and used for the preconcentration of trace amounts of Hg(II) ions in water samples prior to the determination by inductively coupled plasma atomic emission spectrometry.
Abstract: A new modified graphene oxide (GO) was prepared as a solid adsorbent and used for the preconcentration of trace amounts of Hg(II) ions in water samples prior to the determination by inductively coupled plasma atomic emission spectrometry. The method was based on the sorption of analyte on GO which is functionalized by a new ligand: (1-(p-acetyl phenyl)-3-(o-methyl benzoate) triazene (AMBT)). In the adsorption step, central composite design was used to evaluate and determine the optimum level of considered variables (pH, amount of adsorbent and adsorption time). In the desorption step, some factors such as the type, concentration, amount and flow rate of eluting agent were investigated. Many common ions did not interfere. Under the optimal conditions, the adsorption capacity, limit of detection and relative standard deviation were found to be 80 mg g−1, 0.1 μg L−1 and 2.5% (n = 3) respectively. The present method was successfully applied for the determination of mercury ions in real matrix samples.
12 citations
TL;DR: Aryl morpholino triazenes are a new class of compounds that can inhibit cytochrome P450 1A1 and CYP1B1 and potentially prevent cancer.
11 citations
TL;DR: In this article, a continuous-flow process for the preparation of triazenes is described, whereby diazonium salts are generated and converted into their masked or protected triazene derivatives.
Abstract: Herein, we report a continuous-flow process for the preparation of triazenes, whereby diazonium salts are generated and converted into their masked or protected triazene derivatives. Key to realizing the process, which is applicable to a wide range of substrates, is the identification of solvent and reagent parameters that avoid fouling and clogging in the tubing used in these studies. The process has also been applied to prepare the antineoplastic agents mitozolomide and dacarbazine. We also report isolation and differential scanning calorimetry (DSC) analysis of an anthranilic acidderived triazene whose related diazonium salt is a contact explosive. The data highlights improved stability but also suggests that an exothermic process does occur with an onset temperature of 118 °C. Finally, an 18-hour continuous operation of the reaction procedure using high-performance liquid chromatography (HPLC) pumps is reported.
11 citations
01 Mar 2016
TL;DR: In vitro tests, performed in human melanoma cell lines, demonstrated that the incorporation of TPD in liposomes was able to potentiate the cytotoxic effect of this triazene prodrug, representing an excellent approach to fight malignant melanoma.
Abstract: Malignant melanoma remains an aggressive malignancy conferring a very poor prognosis and standard treatments have not demonstrated an overall survival benefits. The alkylating agents triazenes have been used for treatment of malignant melanoma. However, their lack of specificity toward tumor cells requires the urgent development of novel therapeutic strategies. Therefore, the main objectives of the present work were the use of a triazene prodrug, previously synthesized and adequately formulated in liposomes. This triazene prodrug has demonstrated in previous work to be a good substrate for tyrosinase, an enzyme that is overexpressed in melanoma cells. After optimization of liposome preparation conditions and selection of most appropriated lipid compositions, it was possible to achieve high incorporation efficiencies. The association of this prodrug in liposomes, primarily relies in the possibility of solving solubility problems, increasing internalization in melanoma cell lines, protecting the molecule from premature degradation and enhancing its therapeutic index. Prodrug in free and liposomal forms demonstrated a high stability in the presence of human plasma, at 37°C. The in vitro tests, performed in human melanoma cell lines, demonstrated that the incorporation of TPD in liposomes was able to potentiate the cytotoxic effect of this triazene prodrug. The IC50 for the prodrug in free form was superior to 125 μM, whereas in the liposomal form this value ranged from 13 to 22 μM being dependent on the lipid composition. The obtained results represent an excellent approach to fight malignant melanoma.
7 citations
TL;DR: The asymmetric 1,3-disubstituted biaryl triazene 1-(4amidophenyl)-3-(4acetylphenyl)triazene (1) and the corresponding complex [1-(4-amidphenyl)- 3-( 4-acetyl phenyl) triazenido-κN3](triphenylphosphane-κP)gold(I) (2) were characterized by single-crystal X-ray structure analysis and, the antibacterial and the cytotoxic activities of both compounds were investigated RE
7 citations
TL;DR: In this article, the copper-catalyzed arylation of nitrogen heterocycles using anilines via diazonium salts has been studied by combining DFT and experimental data.
7 citations
TL;DR: In this paper, 1-(4-chloro-3-nitrophenyl)-3-(2-methoxyphenyl) triazene, (CNPMPT) structure was synthesized in the laboratory using new experimental methods.
6 citations
TL;DR: In this article, a new ligand 1-(2-biphenyl)-3-methyltriazenide-Noxide (1) and its mononuclear Cu(II) complex (2) were synthesized to verify the capability of this ligand to promote Cu-arene-π interactions.
TL;DR: In this article, a tetranuclear Cu(I)-triazene cluster complex, called Cu4L4, was obtained by the reaction of 1,3-bis(4-bromophenyl) triazene (HL) and [Cu(CH3CN)4]PF6 in THF solvent in the presence of triethylamine.
TL;DR: In this article, a triazenido-platinum complex, Pt(PPh3)2(L)Cl (1), was proposed to catalyze hydrogen generation from acetic acid or a neutral buffer.
Abstract: A new type of electrocatalyst based on a triazenido-platinum complex, Pt(PPh3)2(L)Cl (1), is prepared by the reaction of 1-[(2-methoxy) benzene]-3-[2-pyridine] triazene (HL) and Pt(PPh3)2Cl2 in the presence of triethylamine. Electrochemical studies indicate that HL, Pt(PPh3)2Cl2 and 1 can catalyze hydrogen evolution from acetic acid or a neutral buffer. To show triazenido ligand, HL, plays a role in determining the catalytic activities of the platinum complex, we systematically study the electrocatalytic activities of HL, Pt(PPh3)2Cl2 and Pt(PPh3)2(L)Cl and provide a possible catalytic mechanism for hydrogen generation catalyzed by 1.
TL;DR: In this paper, the first representatives of a new series of 3-monosubstitued functional derivatives of 1-alkoxy-1-triazene 2-oxides were elaborated.
Abstract: Synthetic procedure to access the first representatives of a new series of 3-monosubstitued functional derivatives of 1-alkoxy-1-triazene 2-oxides, i.e., 1-alkoxy-3-(2-hydroxyethyl)- and 1-alkoxy-3-(2-acetoxyethyl)-1-triazene 2-oxides, were elaborated. 1-Alkoxy-3,3-bis(2-hydroxyethyl)-1-triazene 2-oxides were used to derive 3-(2-acetoxyethyl)-, 3-(2-bromoethyl)- and 3-(2-cyanoethyl)substituted 1-alkoxy-3-(2-acetoxyethyl)-1-triazene 2-oxides.
05 Feb 2016
TL;DR: In this article, a 5-bromo compound with NaN3.2 was synthesized from the corresponding 5-amino compound, and the crystal structures of three nitrogen-rich salts were determined.
Abstract: 5-Azido-4-(dimethylamino)-1-methyl-1,2,4-triazolium hexafluoridophosphate was synthesized from the corresponding 5-bromo compound with NaN3. Reaction with bicyclo[2.2.1]hept-2-ene yielded a tricyclic aziridine, addition of an N-heterocyclic carbene resulted in a triazatrimethine cyanine, and reduction with triphenylphosphane gave the 5-amino derivative. The crystal structures of three nitrogen-rich salts were determined. Thermoanalysis of the cationic azide and triazene showed exothermal decomposition. The triazene exhibited negative solvatochromism in polar solvents involving the dipolarity π* and hydrogen-bond donor acidity α of the solvent.
TL;DR: The chemical reactivity of stable triazene 3 toward some nucleophilic and electrophilic reagents was investigated in this article, where Traizene 3 was used as a key precursor for the synthesis of some novel important heterocyclic compounds such as Pyrazole, Isoxazole, Dihydropyrimidine, Tetrahydro-pyridine derivatives with expected antimicrobial activity.
Abstract: The chemical reactivity of novel stable triazene 3 toward some nucleophilic and electrophilic reagents was investigated. Traizene 3 was used as a key precursor for the synthesis of some novel important heterocyclic compounds such as Pyrazole, Isoxazole, Dihydropyrimidine, Tetrahydro-pyridine derivatives with expected antimicrobial activity. The synthesized compounds were obtained in good yields. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H-NMR and Ms spectral data.
TL;DR: In this paper, the geometric structure of complex 1 is optimized by B3LYP, PBE0, and M06 methods with the same mixed 6-31G(d)-LANL2DZ basis set.
Abstract: Two compounds 1-[(2-carboxymethyl)benzene]-3-[2-pyridine]triazene (HL) and 1-[(2-carboxymethyl) benzene]-3-[o-aminobenzoic acid]triazene (H2L') and two corresponding Pt(II) complexes, Pt(PPh3)2(L)Cl (1) and Pt(PPh3)2(L') (2), are theoretically studied by the density functional theory and time-dependent density functional theory. The geometric structure of complex 1 is optimized by B3LYP, PBE0, and M06 methods with the same mixed 6-31G(d)-LANL2DZ basis set. The absorption spectrum of complex 1 is simulated by the above method. As compared with the experimental data, the combination of M06/6-31G(d)-LANL2DZ and TD-M06/6-31G(d)-LANL2DZ is chosen for all other calculations including optimization of the ground-state and the lowest triplet excited state geometries, and the absorption and emission spectra. The detailed electronic transitions are analyzed to understand deeply the properties of spectra. Mobility of holes and electrons in 2 are studied computationally based on the Marcus theory. The ionization potential and electron affinity of complex 2 are calculated to evaluate qualitatively the hole- and electron-injection properties, respectively. Its potential as a dopant for phosphorescent OLEDs is explored.
TL;DR: In this article, a general and practical synthetic method for the construction of unsymmetrically substituted diphenyldiazenes based on classical azo coupling reaction has been developed.
TL;DR: In this article, the triazene group is removed with trifluoroacetic acid and, because of the low barrier to rotation, affords sharp 1H NMR spectra at room temperature.
Abstract: Selective protection of secondary amines as triazenes in the presence of multiple primary amines is demonstrated, with subsequent protection of the primary amines as either azides or carbamates in the same pot. Aminoglycoside antibiotic examples reveal broad functional group compatibility. The triazene group is removed with trifluoroacetic acid and, because of the low barrier to rotation, affords sharp 1H NMR spectra at room temperature.
TL;DR: In this paper, the structure analysis by single crystal X-ray diffraction of compounds (1 ) and (2 ) demonstrate the formation of 3D supramolecular arrangements through ion-ion, ion-dipolo and dipolo-Dipolo interactions.
Patent•
07 Dec 2016
TL;DR: In this article, a method for detecting heavy metal ions by triazene reagents has been proposed, which solves the problem in the prior art that detection of heavy metal ion using triazenes has a low sensitivity and unideal selectivity.
Abstract: The invention belongs to the field of bistriazene compounds, and solves the problem in the prior art that detection of heavy metal ions by triazene reagents has a low sensitivity and unideal selectivity. The method comprises the following steps: firstly, NaHSO3, formaldehyde and aniline are used for preparing a settled solution of sodium aniline methyl sulfonate, sulfanilic acid is used for preparing a solution of diazonium salt, the two kinds of solution are mixed, and 4-amino-4'-azobenzene sulfonic acid; secondly, 2,6-diamino pyridine, KNO3 solid and fuming nitric acid are used, in order to produce 3,5-dinitro-2,6-diamino pyridine; thirdly, two kinds of substances prepared by the two steps are produced into a solution, after a reaction, produced products are separated by column chromatography, and 3,5-dinitro-2,6-bis(4,4'-sulfonic azobenzene azo amino)pyridine. Pyridine is a high-sensitivity developer for measuring cadmium by a photometric method, and measurement of cadmium is good selectivity.
TL;DR: In this article, the 1-triazolyl-3-benzimidazolyltriazene (H3TBIT) ligand of [Co(H2TBIT)(HTBIT)] was synthesized and characterized by single crystal X-ray diffraction analysis.
Abstract: Four transition metal complexes based on the 1-triazolyl-3-benzimidazolyltriazene (H3TBIT) ligand of [Co(H2TBIT)(HTBIT)] (1), {[Cu(H2TBIT)(SCN)]·H2O} (2), [Cd2(H3TBIT)2(H2O)2Cl4] (3) and {[Ni3(H2TBIT)2(HTBIT)2(en)2]·IPA·2H2O} (en = ethylenediamine, IPA = isopropanol) (4) have been synthesized and characterized by single crystal X-ray diffraction analysis. In 1–4, the triazene ligand acts in different coordinating or bridging modes resulting in two mononuclear structures for 1 and 2, one dinuclear structure for 3 and one trinuclear structure for 4. Different structural 1–4 are further self-assembled through hydrogen bonds or π–π, C–H⋯π or metal–π interactions to form 3D supramolecular structures. The electrochemical properties in aqueous solutions as well as the photoluminescent properties in ethanol of H3TBIT and 1–4 are investigated. The TD-DFT calculations at the B3LYP/6-311++G(d,p) level for H3TBIT has been used to demonstrate the characteristic absorption spectrum.
01 Jan 2016
TL;DR: In this paper, triazene derivatives were designed and synthesized by combination of triazenes and 1,3,4-oxadiazoles, and the target compounds were characterized by H NMR, IR and HRMS.
Abstract: 11 novel 1,3,4-oxadiazole triazene derivatives were designed and synthesized by combination of triazenes and 1,3,4-oxadiazoles All the target compounds were characterized by H NMR, IR and HRMS The antitumor activities of all compounds were screened by using thiazolylblue (MTT) assay in vitro, in which MGC803 cell lines and PC-3 cell lines were used as the test cancer cell The results showed that compounds 2-(4-(3,3-dimethyltriaz-1-en-1yl)phenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole (b4), 2-(4-(3,3-dimethyltriaz-1-en-1-yl)phenyl)-5-(2-methoxyphenyl)-1,3,4-oxadiazole (b9), 2-(4-(3,3-dimethyltriaz-1-en-1-yl)phenyl)-5-(benzo[d][1,3]dioxol-5-yl)-1,3,4-oxadiazole (b10) and 2-(4-(3,3-dimethyltriaz-1en-1-yl)phenyl)-5-(pyridin-4-yl)-1,3,4-oxadiazole (b11) exhibited higher activity against PC-3 cell than control compound dacarbazine (DTIC), and their IC50 values were 74145, 87790, 87327 and 104875 μmol/L, respectively But all compounds had little inhibition effect on MGC803 cell lines All synthesized compounds were screened by broth dilution technique for their fungicidal activity against S aureus and E coli The antibacterial activity results showed that all of compounds were inactive
Patent•
13 Jul 2016
TL;DR: In this article, a double triazene reagent was used for detecting heavy metal ions through photometric analysis, but the interference from coexisting ions is strong, sensitivity and selectivity are not ideal enough, and the existing triazenes cannot be taken as a fluorescent reagent for fluorescence detection of the heavy metal ion.
Abstract: The invention belongs to the technical field of double triazene compounds and provides 3,3'-dimethylthio-4,4'-bis(2,6-dichloro-4-nitrophenyl diazoamino) biphenyl, a preparation method and an application in order to solve the problems that when an existing triazene reagent is used for detecting heavy metal ions through photometric analysis, interference from coexisting ions is strong, sensitivity and selectivity are not ideal enough and the existing triazene reagent cannot be taken as a fluorescent reagent for fluorescence detection of the heavy metal ions. 3,3'-dimethylthio-4,4'-diaminodiphenyl and 2,6-dichloro-4-nitrophenyl are linked together through a triazene functional group -N=N-NH-, and a prepared reagent is not only a photometric analysis reagent with good sensitivity and selectivity, but also is a fluorescence analysis reagent with a high fluorescence characteristic. The sensitivity of the reagent for measuring mercury with a photometric method is improved; the reagent is a fluorescent lead (II) measurement reagent with good sensitivity and selectivity; the allowed coexistence number of common interfering ions is greatly increased; a synthetic method is simple, conditions are mild, and complexes formed by a solid reagent and a reagent solution with mercury are all stable.
Patent•
21 Dec 2016
TL;DR: In this article, with the diazotization reaction and coupling reaction, 3,5-dimethylthio-2,4-diaminotoluene and p-aminonitro azobenzene are adopted as the raw materials to synthesize the novel bis triazene reagent.
Abstract: The invention belongs to the technical field of bis triazene compounds. In the prior art, the reagent for heavy metal ion detection has low sensitivity and the selectivity is not ideal. With the present invention, the problems in the prior art can be solved. According to the present invention, with the diazotization reaction and the coupling reaction, 3,5-dimethylthio-2,4-diaminotoluene and p-aminonitro azobenzene are adopted as the raw materials to synthesize the novel bis triazene reagent, wherein the synthesized bis triazene reagent is the luminosity analysis reagent with characteristics of high sensitivity and good selectivity, and is the fluorescent reagent having the strong fluorescence characteristic.
TL;DR: In this paper, a general and practical synthetic method for the construction of unsymmetrically substituted diphenyldiazenes based on classical azo coupling reaction has been developed.
Abstract: A general and practical synthetic method for the construction of unsymmetrically substituted diphenyldiazenes based on classical azo coupling reaction has been developed. A key feature of this method is the use of N,N-diallyl protected aniline derivatives as coupling components. The N,N-diallyl moiety of the coupling component warrants sufficient reactivity and allows to avoid formation of constitutional isomers resulting from intermediate triazene formation. Furthermore, subsequent to the coupling reaction, the N,N-diallyl aminofunction, can be replaced by other substituents including hydrogen via diazonium ion intermediates. In general, following this approach target compounds can be obtained in reasonable to good yields.
TL;DR: In this paper, the effect of some hydroxytriazenes on copper in nitric acid medium has been studied using weight loss technique at temperature range between 303 to 343 K.
Abstract: Inhibition effect of some hydroxytriazenes on copper in nitric acid medium has been studied using weight loss technique at temperature range between 303 to 343 K. The used hydroxytriazene compounds are 3-Hydroxy-3-phenyl-1-(4-sulphonato(sodium salt) phenyl) triazene(HPST), 3-Hydroxy-3-(3-methylphenyl)- 1-(4-sulphonato(sodium salt) phenyl) triazene(HMMPST), 3-Hydroxy-3-(4-methylphenyl)-1-(4-sulphonato (sodium salt) phenyl) triazene (HPMPST), 3-Hydroxy-3-(3-chloroplenyl-(4-sulphonato (sodiumsalt) phenyl) triazene (HMCPST), 3-Hydroxy-3-(4-chloroplenyl-(4-sulphonato (sodiumsalt)phenyl) triazene (HPCPST). Results reveal that inhibition efficiency increases with increasing concentration of hydroxytriazenes from 0.0005 to 0.002 M in following order HPMPST > HPST > HMMPST > HPCPST > HMCPST. HPMPST compound in 0.002M concentration show maximum inhibition efficiency of ~90 at % 303 K temperature. Effect of temperature on inhibition efficiency and thermodynamic parameters have also been reported. The adsorption of hydroxytriazenes obeyed Langmuir Adsorption Isotherm.