Triazene derivatives of (1,x)-diazacycloalkanes. Part V.1 Synthesis and characterization of 4-ethyl-3-({6-ethyl-3-[2-aryl-1-diazenyl]hexahydro-1-pyrimidinyl}methyl)-1-[2-aryl-1-diazenyl)hexa- hydropyrimidines from the reaction of diazonium salts with mixtures of formaldehyde and 1,3-diaminopentane

2005 ◽  
Vol 83 (10) ◽  
pp. 1799-1807 ◽  
Author(s):  
Reid Tingley ◽  
M Brad Peori ◽  
Ryan Church ◽  
Keith Vaughan

A new series of bistriazenes has been synthesized from a general reaction of diazonium salts with a mixture of 1,3-diaminopentane (DYTEK® EP diamine) and formaldehyde, which affords the 4-ethyl-3-({6-ethyl-3-[2-aryl-1-diazenyl]hexahydro-1-pyrimidinyl}methyl)-1-[2-aryl-1-diazenyl]hexahydropyrimidines (1). Each of the molecules of type 1 is built up of two equivalent 3-(aryldiazenyl)-6-ethylhexahydro-1-pyrimidinyl groups attached to a central methylene group. The importance of this study is in part due to the fact that the formaldehyde–1,3-diaminopentane system has not previously been investigated. All new compounds have been characterized by IR and NMR spectroscopy, with elemental analysis for selected compounds; one example from the series has been unequivocally characterized by X-ray crystallography. Although analysis of the NMR spectra is made somewhat difficult because of broadness and coalescence of signals due to the rotational dynamics of the N—N single bonds, it is possible to fully assign the proton spectra of all compounds and to detect 94% of all carbon signals. The fine structure within the proton spectra illustrate the diastereotopic nature of the methylene group protons because of the presence of a stereocenter in each hexahydropyrimidine ring. The general conclusion of this study is that alkanediamines with three carbon atoms in the spacer link between the nitrogen atoms give rise to the linear bicyclic molecules of type 1, 2, and 3, in contrast to the case of ethylenediamine (spacer link has two carbon atoms), which affords molecules of type 7 that exemplify the bridged bicyclic bistriazene structure. The new compounds of series 1 represent an extension of a broad ranging study of the synthesis of new bistriazene derivatives of (1,x)-diazacycloalkanes.Key words: triazene, diazonium coupling, hexahydropyrimidine, diaminopentane, diazacycloalkanes, stereocenter, diastereotopic protons.

2005 ◽  
Vol 83 (8) ◽  
pp. 1071-1083 ◽  
Author(s):  
Shasta Moser ◽  
Ryan Church ◽  
M Brad Peori ◽  
Keith Vaughan

Two new series of bistriazenes have been synthesized from a general reaction of diazonium salts with a mixture of a propanediamine and formaldehyde. Such reaction with 1,3-diaminopropane itself affords the 1-[2-aryl-1-diazenyl]-3-(3-[2-aryl-1-diazenyl]hexahydro-1-pyrimidinylmethyl)hexahydropyrimidines (6). 2,2-Dimethyl-1,3-diamino propane reacts in an analogous manner to give the 1-(5,5-dimethyl-3-[2-aryl-1-diazenyl]hexahydro-1-pyrimidinylmethyl)- 5,5-dimethyl-3-[2-aryl-1-diazenyl]hexahydropyrimidines (7). All new compounds have been characterized by IR and NMR spectroscopy, with elemental analysis or high resolution mass spectrometry of most of the new compounds. NMR assignments have been analyzed by a series of DEPT, COSY, and HSQC experiments. One example of each series has been unequivocally characterized by X-ray crystallography. The general conclusion of this study is that alkanediamines with three carbon atoms in the spacer link between the nitrogen atoms give rise to the linear bicyclic molecules of type 18, in contrast to the case of ethylenediamine (spacer link has two carbon atoms), which affords cage-like molecules of type 17.Key words: bistriazene, hexahydropyrimidine, diazonium coupling, formaldehyde, diaminopropane, nuclear magnetic resonance.


2006 ◽  
Vol 84 (10) ◽  
pp. 1434-1441
Author(s):  
Reid Tingley ◽  
Keith Vaughan

A new series of bistriazenes, the 1-aryl-2-[3-(3-[2-aryl-1-diazenyl]-1,3-diazepan-1-ylmethyl)-1,3-diazepan-1-yl]-1-diazenes (8), has been synthesized from the reaction of diazonium salts with a mixture of 1,4-diaminobutane and formaldehyde. All new compounds of series 8 have been characterized by IR and NMR spectroscopy, and the elemental composition of selected examples has been verified by elemental analysis. The connectivity of the series has been unequivocally determined by X-ray crystallography. The new bistriazenes are important because the structure contains the novel saturated heterocycle, 1,3-diazepane. The general conclusion of this study is that alkanediamines with three or four carbon atoms in the spacer link between the nitrogen atoms give rise to the linear bicyclic molecules of type 2, in contrast to the case of ethylenediamine (two carbon atoms in spacer link), which affords molecules of type 3, which exemplify the cage structure of type 1.Key words: diazonium salt, triazene, bistriazene, diazepane, formaldehyde, nuclear magnetic resonance.


2010 ◽  
Vol 88 (4) ◽  
pp. 344-351 ◽  
Author(s):  
Naomi Hunter ◽  
Keith Vaughan

A series of 1,4-di-[2-aryl-1-diazenyl]-2,6-dimethylpiperazines (5a–5l), have been synthesized by the reaction of 2,6-dimethylpiperazine with 2 equiv. of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by high-resolution EI mass spectrometry with accurate mass measurement of the molecular ion. The presence of stereocenters at C2 and C6 of the piperazine ring in the bis-triazene 5 creates two unique pairs of diastereotopic protons in the methylene groups at positions 3 and 5 of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in most cases. The assignment of the proton and carbon signals in the 1,4-di-[2-aryl-1-diazenyl]-2,6-dimethylpiperazines has been aided by the use of 2D NMR HSQC spectroscopy. These results compare favorably with assignments of proton and carbon signals reported previously for triazenes of type 1 and bis-triazenes of type 3.


2005 ◽  
Vol 83 (5) ◽  
pp. 471-476 ◽  
Author(s):  
Vanessa Renée Little ◽  
Reid Tingley ◽  
Keith Vaughan

Reaction of a series of diazonium salts with piperazine in a 2:1 molar ratio affords excellent yields of the 1,4-di-[2-aryl-1-diazenyl]piperazines (3), which have been characterized by IR and NMR spectroscopy. Structural characterization is supported by elemental analysis or by mass spectrometry with accurate mass measurement of the molecular ion. The protons of the piperazine ring hydrogens give rise to a sharp singlet at ca. 4 ppm in the NMR spectra, indicating that the conformational equilibrium in the piperazine ring is rapid on the NMR timescale. The four equivalent carbon atoms of the piperazine ring resonate in the range 46–48 ppm. A variable temperature NMR experiment suggests that there is restricted rotation around the N2—N3 bond of the triazene moiety in 3. The NMR data compares favorably with previous reported data for 1-aryldiazenyl-4-methylpiperazines (1) and 1,4-di-(2-aryldiazen-1-yl)homopiperazines (2b).Key words: triazene, piperazine, diazonium coupling, NMR.


2014 ◽  
Vol 92 (7) ◽  
pp. 665-669 ◽  
Author(s):  
Vanessa Renee Little ◽  
Reid Tingley ◽  
Keith Vaughan

A series of 1,4-di[2-aryl-1-diazenyl]-trans-2,5-dimethylpiperazines(5a–5m), have been synthesized by the reaction of trans-2,5-dimethylpiperazine with two equivalents of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by high-resolution EI mass spectrometry with accurate mass measurement of the molecular ion. The presence of stereocenters at C2 and C5 of the piperazine ring in the bis-triazene (5) creates two unique pairs of diastereotopic protons in the methylene groups at positions 3 and 6 of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in some cases, such as the anisyl- (5i) and phenyl- (5j) derivatives. The assignment of the proton and carbon signals in the tolyl- derivative (5h) has been aided by the use of 2D NMR HSQC spectroscopy. These results compare favorably with assignments of proton and carbon signals reported previously for triazenes of type 1 and bis-triazenes of types 3 and 4b.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4160
Author(s):  
Speranta Avram ◽  
Ana Maria Udrea ◽  
Diana Camelia Nuta ◽  
Carmen Limban ◽  
Adrian Cosmin Balea ◽  
...  

(1) Background: The research aims to find new treatments for neurodegenerative diseases, in particular, Alzheimer’s disease. (2) Methods: This article presents a bioinformatics and pathology study of new Schiff bases, (EZ)-N′-benzylidene-(2RS)-2-(6-chloro-9H-carbazol-2-yl)propanehydrazide derivatives, and aims to evaluate the drug-like, pharmacokinetic, pharmacodynamic and pharmacogenomic properties, as well as to predict the binding to therapeutic targets by applying bioinformatics, cheminformatics and computational pharmacological methods. (3) Results: We obtained these Schiff bases by condensing (2RS)-2-(6-chloro-9H-carbazol-2-yl)propanehydrazide with aromatic aldehydes, using the advantages of microwave irradiation. The newly synthesized compounds were characterized spectrally, using FT-IR and NMR spectroscopy, which confirmed their structure. Using bioinformatics tools, we noticed that all new compounds are drug-likeness features and may be proposed as potentially neuropsychiatric drugs (4) Conclusions: Using bioinformatics tools, we determined that the new compound 1e had a high potential to be used as a good candidate in neurodegenerative disorders treatment.


2006 ◽  
Vol 84 (10) ◽  
pp. 1294-1300 ◽  
Author(s):  
Keith Vaughan ◽  
Shasta Lee Moser ◽  
Reid Tingley ◽  
M Brad Peori ◽  
Valerio Bertolasi

Reaction of a series of diazonium salts with a mixture of formaldehyde and 1,2-diamino-2-methylpropane affords the 3-({5,5-dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines (1a–1f) in excellent yield. The products have been characterized by IR and NMR spectroscopic analysis, elemental analysis, and X-ray crystallography. The X-ray crystal structure of the p-methoxycarbonyl derivative (1c) establishes without question the connectivity of these novel molecules, which can be described as linear bicyclic oligomers with two imidazolidinyl groups linked together by a one-carbon spacer. This is indeed a rare molecular building block. The molecular structure is corroborated by 1H and 13C NMR data, which correlates with the previously published data of compounds of types 5 and 6 derived from 1,3-propanediamine. The triazene moieties in the crystal of 1c display significant π conjugation, which gives the N—N bond a significant degree of double-bond character. This in turn causes restricted rotation around the N—N bond, which leads to considerable broadening of signals in both the 1H and 13C NMR spectra. The molecular ion of the p-cyanophenyl derivative (1b) was observed using electrospray mass spectrometry (ES + Na). The mechanism of formation of molecules of type 1 is proposed to involve diazonium ion trapping of the previously unreported bisimidazolidinyl methane (13).Key words: triazene, bistriazene, imidazolidine, synthesis, X-ray crystallography, NMR spectroscopy.


2015 ◽  
Vol 70 (8) ◽  
pp. 541-546 ◽  
Author(s):  
Muhammad Nawaz Tahir ◽  
Anvarhusein A. Isab ◽  
Fozia Afzal ◽  
Kashif Raza ◽  
Shah Muhammad ◽  
...  

AbstractSilver(I) complexes of thioureas and thiocyanate, [(Tu)AgSCN], [(Metu)AgSCN], [(Dmtu)AgSCN], [(Tmtu)(AgSCN)1.5], [(Imt)AgSCN], and [(Diaz)AgSCN] (where Tu = thiourea, Metu = N-methylthiourea, Dmtu = N,N′-dimethylthiourea, Tmtu = N,N,N′,N′-tetramethylthiourea, Imt = 1,3-imidazolidine-2-thione, and Diaz = 1,3-diazinane-2-thione), have been prepared and characterized by elemental analysis, IR and NMR spectroscopy, and thermal analysis. The crystal structure of one of them, [(Diaz)Ag(SCN)] (1), was determined by X-ray crystallography. The crystal structure of 1 shows that the complex exists in the form of a chain-like polymer comprising [Ag(μ2-Diaz)(μ2-SCN)] units. The silver atoms are bridged by μ2-thione sulfur atoms of Diaz and μ2-thiocyanate sulfur atoms. Thereby each silver atom adopts a distorted tetrahedral coordination environment comprising four sulfur atoms, two from thione and two from thiocyanate ligands. An upfield shift in the >C=S resonance of thiones in 13C NMR and a downfield shift in the N–H resonance in 1H NMR are consistent with the sulfur coordination to silver(I). The appearance of a band around 2100 cm–1 in the IR and a resonance around 125 ppm in the 13C NMR spectrum indicates the binding of thiocyanate to silver(I).


1986 ◽  
Vol 64 (4) ◽  
pp. 751-759 ◽  
Author(s):  
Daniel Cozak ◽  
Abdelhakim Mardhy ◽  
André Morneau

The reaction of CpTi(CO)2 (1), Cp2TiCl (2), and Cp2TiCl2 (3) (Cp = η5-C5H5) with purine (PuH) and adenine (AdH) in organic solvents is described. The compound 1 reacts with both molecules in an oxidative fashion giving Cp2Ti(C5H3N4)(C5H4N4) (4) and (Cp2Ti)2(C5H3N5) (5) with concomitant liberation of molecular carbon monoxide and hydrogen (4:1) following a first order rate law in metal complex. The compound 2 forms an adduct compound Cp2TiCl(C5H4N4) (6) with PuH. Monosubstituted derivatives Cp2TiCl(C5H3N4) (7) and Cp2TiCl(C5H4N5) (8) are formed from the reaction of the deprotonated bases with 3. In addition to the usual elemental analysis, the characteristic ir, 1H nmr, epr, and ms results are given for the new compounds.


2004 ◽  
Vol 82 (12) ◽  
pp. 1725-1735 ◽  
Author(s):  
Shasta Lee Moser ◽  
Keith Vaughan

1-Methylhomopiperazine was coupled with a series of diazonium salts to afford the 4-methyl-1-[2-aryl-1-diazenyl]-1,4-diazepanes (6), a new series of triazenes. These compounds are, in the main, stable crystalline solids (some of the series are stable oils), and they have been characterized by 1H and 13C NMR spectroscopy, IR spectroscopy, and mass spectrometry. NMR assignments were determined by 2D NMR and variable-temperature NMR experiments and by comparison with model compounds. A second series of new compounds, namely, 1,4-di-[2-aryl-1-diazenyl]-1,4-diazepanes (5), were prepared by coupling unsubstituted homopiperazine (1,4-diazepane) with 2 molar equivalents of the diazonium salt and were similarly characterized. The crystal and molecular structure of the parent member of this bis-triazene series (5, X = H) has been determined by single-crystal X-ray diffraction analysis.Key words: triazene, bis-triazene, diazenyl, bis-diazenyl, diazonium salt, NMR, diazepane.


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