7227-92-1Relevant academic research and scientific papers
Alternative method for the synthesis of triazenes from aryl diazonium salts
Abrams
, (2021/05/10)
An alternative mild method for access to 1-aryl-3,3-dimethyl alkyl triazenes is described. This protocol employs the dropwise addition of a methanolic solution of a carboxylate (RCO2M) or carbonate (CO32?) to a gently heated DMF solution containing an aryl diazonium salt (ArN2+), that had been previously isolated. Presumably homolysis of the weak N–O bond of diazo ether adducts formed in this operation initiates radical pathways that lead to the generation of triazene product. DMF serves as not only a one-electron donor to the diazonium salts employed in this process, but also as a source of dimethylamine radicals that act as a nucleophilic coupling partner. The reaction provides modest yields (ca. 20–40%) across an array of aryl diazonium salts that contain various substitution. Furthermore this unique approach to triazenes contrasts with traditional methods that employ dimethyl amine in reagent form which directly couples with diazonium salts. Seemingly, only one other example employing somewhat similar reaction conditions to this current investigation en route to triazenes has been reported, albeit with lower yields and for one representative example furnished as a side-product. The current work here improves upon the efficiency of this reported result, and further expands the reaction scope.
Highly efficient palladium-catalyzed cross-coupling of diarylborinic acids with arenediazoniums for practical diaryl synthesis
Wang, Fengze,Wang, Chen,Sun, Guoping,Zou, Gang
supporting information, (2019/12/25)
A highly efficient cross-coupling of cost-effective diarylborinic acids with both isolatable and latent arenediazoniums, i.e. tetrafluoroborates and aryltriazenes, respectively, has been developed with a practical palladium catalyst system under base-free conditions in open flask at room temperature. A variety of electronically and sterically various biaryls, in particular, those bearing a coordinative ortho-substituent, could be obtained in good to excellent yields by using 0.3 mol% palladium acetate as catalyst. Features of the protocol including cost-effectiveness of diarylborinic acids, efficacy to heteroatom ortho-substituted substrates and high chemoselectivity to aryl chlorides have been clearly demonstrated in practical synthesis of fungicide Boscalid.
Diazo reactions with unsaturated compounds: XII. Reaction of 1-(p-Carboxybenzenesulfonyl)-1,3-butadiene with aryldiazonium chlorides, 1-aryl-3,3-dimethyl-1-triazenes, and aryldiazonium tetrachlorocuprates(II)
Smalius,Naidan
, p. 586 - 588 (2008/02/11)
1-(p-Carboxybenzenesulfonyl)-1,3-butadiene reacts in aqueous acetone with aryldiazonium chlorides and 1-aryl-3,3-dimethyl-1-triazenes in the presence of copper(II) chloride and with tetrachlorocuprates(II) to form 1-(p-carboxybenzenesulfonyl)-4-aryl-3-chloro-1-butenes. Nauka/Interperiodica 2007.
Synthesis, physicochemical characterization and preliminary pharmacological in vitro evaluation of two novel cytotoxic benzophenone-linked 3,3-dimethyltriazenes
Manolov, Ilia,Machulla,Momekov
, p. 511 - 516 (2007/10/03)
The synthesis, physicochemical characterization and preliminary pharmacological evaluation of the cytotoxic effects of two novel substances, 1-(4-benzoylphenyl)-3,3-dimethyllriazene and 1-(2-benzoylphenyl)-3,3- dimethyltriazene is presented. The cytotoxicity of the novel benzophenone-linked triazenes and of ten other 1-phenyl-3,3-dimethyl triazene derivatives as well as of the referent alkylating drug melphalan was assessed using the MTT-dye reduction assay. A panel of human tumor cell lines was used: the chronic lymphoid leukemia SKW-3, the acute promyelocyte leukemia HL-60 and its multidrug-resistant subline HL-60/Dox. Both novel compounds showed strong cytotoxic activity, comparable to that of the referent alkylating agent melphalan, whereas the ten ring-substituted 1-phenyl-3,3-dimethyl triazenes proved to be far less active in vitro. DNA-fragmentation analysis indicated that after 24 h treatment the novel benzophenone-linked triazenes induced programmed cell death in HL-60 cells.
1-Aryl-3,3-dialkyltriazenes: A convenient synthesis from dry arenediazonium o-benzenedisulfonimides - A high yield break down to the starting dry salts and efficient conversions to aryl iodides, bromides and chlorides
Barbero,Degani,Diulgheroff,Dughera,Fochi
, p. 2180 - 2190 (2007/10/03)
This research comprises three parts. The first part regards the synthesis of 1-aryl-3,3-dialkyltriazenes 3 by reaction of dry arenediazonium o-benzenedisulfonimides 1, also coming from weakly basic aromatic amines with dimethylamine or diethylamine in aqueous solution at 0-5 °C. Yields were usually greater than 90% and there was the possibility of recovering the o-benzenedisulfonimide (5), which could be reused to prepare the salts 1. In the second part it was demonstrated that there is the possibility of reconverting the triazenes 3 into the starting stable dry salts 1 by using 5 as acid. The reactions were carried out in glacial acetic acid at 50-55 °C and normally afforded salts 1 in yields of around 90-99%. The third part concerns the setting up of two procedures for the conversion of 3 to aryl iodides 9, bromides 10 and chlorides 11. Procedure A used the corresponding aqueous hydrogen halides in acetonitrile at r.t. or 60 °C, sometimes in the presence of aqueous HBF4, sometimes Cu powder (25 examples, yields 65%-88%). Procedure B usually used anhydrous methanesulfonic acid and tetraalkylammonium halides in anhydrous acetonitrile at temperatures varying from r.t. to 80 °C, sometimes in the presence of Cu (16 examples, yields 65-88%).
Waste-Free Quantitative Gas/Solid Diazotation Using Nitrogen Dioxide and Triazene Synthesis, Both Avoiding Liquid Phases
Kaupp, Gerd,Herrmann, Andreas
, p. 256 - 260 (2007/10/03)
Solid diazonium nitrates (2a-j) are quantitatively obtained by reaction of crystalline anilines (1a-j) with gaseous nitrogen dioxide. Solid diazonium salts react quantitatively with dimethylamine to give the triazenes (4a-j). Wastes that are typical for the previous syntheses of these compounds in solution are avoided. Atomic force microscopic (AFM) investigations indicate long-range molecular movements due to phase rebuilding. The features thus formed are related to the known crystal structures of the starting anilines. The diazotations run to completion, because, after accumulation of product molecules, phase transformation to give the product lattices leads to crystal disintegration and thus to formation of fresh surface over and over.
Protodediazoniation of aryldiazonium fluoroborates by dimethylformamide
Markgraf, J. Hodge,Chang, Raymond,Cort, John R.,Durant Jr., Joseph L.,Finkelstein, Manuel,Gross, Andrew W.,Lavyne, Michael H.,Moore, W. Michael,Petersen, Raymond C.,Ross, Sidney D.
, p. 10009 - 10018 (2007/11/02)
The protodrdiazoniation of aryldiazonium fluoroborates can be effected by warm dimethylformamide (DMF). The conversion of 4-nitrobenzenediazonium fluoroborate to nitrobenzene was studied in detail. Products derived from trapping experiments were consistent with a homolytic process. Studies with deuterated DMF established that H atom abstraction occurred from both sites in DMF with a formyl:methyl preference of 3.5:1.0. This mechanism was consistent with bond energies and kinetic isotope effects calculated for the DMF radical cation.
13C and 1H Nuclear Magnetic Resonance Study of Solvent Effects on Tautomerism in 1-Aryl-3-methyltriazenes
Hooper, Donald L.,Vaughan, Keith
, p. 1161 - 1165 (2007/10/02)
13C and 1H n.m.r. spectra of 1-p-tolyl- (II) and 1-p-nitrophenyl-3-methyltriazene (III) have been recorded in CDCl3 at variable temperatures and in DMSO solutions at ambient temperature.Assignment of 13C and 1H signals to one or both of the tautomeric species (ArN=N.NHCH3 or ArNH.N=NCH3) has been carried out with the aid of gated decoupling and full 1H decoupling methods and by comparison of chemical shifts with those of the model compounds p-nitroaniline, 3,3-dimethyl-1-p-nitrophenyltriazene, and 3-methyl-1,5-di-(p-tolyl)-pentaza-1,4-diene(IV).The 13C spectrum of(II) in CDCl3 shows signals assigned to the conjugated tautomer (IIa), but not the unconjugated tautomer (IIb); additional signals in the 13C spectrum of (II) are shown to arise from the pentaazadiene (IV), which is present as an impurity (ca. 10percent) in commercial samples of (II). 1H and 13C spectra of (IV) have been completely assigned.The tautomeric equilibrium (IIa) -->/DMSO as solvent, so much so that two full sets of aromatic peaks are visible in the 13C spectrum of (II) in DMSO at room temperature and the 1H spectrum clearly shows signals unequivocally assigned to the unconjugated tautomer (IIb).The equilibrium (IIa) -->//DMSO and the 1H spectra of (III) in DMSO and the 1H spectra of (III) in DMSO or in CDCl3 at room temperature also show the presence of both tautomers.The relative proportions of tautomers (IIIa) : (IIIb) was found to be 49 : 51 in DMSO.
