304-81-4Relevant articles and documents
Cu-Catalyzed π-Core Evolution of Benzoxadiazoles with Diaryliodonium Salts for Regioselective Synthesis of Phenazine Scaffolds
Sheng, Jinyu,He, Ru,Xue, Jie,Wu, Chao,Qiao, Juan,Chen, Chao
supporting information, p. 4458 - 4461 (2018/08/09)
The Cu-catalyzed regioselective synthesis of phenazine N-oxides was realized from benzoxadiazoles and diaryliodonium salts. The process was initiated by the electrophilic arylation of benzoxadiazoles with diaryliodonium salts and followed by benzocyclization reactions. The further reduction of N-oxides in situ to phenazine scaffolds and deviation to organic fluorescent materials were readily accomplished.
THE PHOTOCYCLIZATION OF N-ACYL-2-NITRODIPHENYLAMINES TO PHENAZINE N-OXIDES: SCOPE AND MECHANISM
Fasani, Elisa,Pietra, Silvio,Albini, Angelo
, p. 573 - 584 (2007/10/02)
The photocyclization of N-acyl-2-nitridiphenylamines to phenazine N-oxides is extended to several dinitro derivatives and a pyridine analogue obtaining N-oxides of otherwise difficult access.In the presence of some additives, the reaction takes a different course.Thus, with acids deacylation occurs, with triphenylphosphine a N-phosphoranylidene amine is formed and with 2,6-di-tert-butylphenol the corresponding nitrosodiphenylammine is obtained.A mechanism starting from the nitroamide triplet and involving several discrete intermediates is proposed in order to account for such observations.
Photochemical Reaction of 2,4-Dinitrodiphenylacetamide and Related Compounds: Spectroscopic and Chemical Identification of Intermediates
Fasani, Elisa,Mella, Mariella,Albini, Angelo
, p. 2689 - 2692 (2007/10/02)
2,4'-Dinitrodiphenylacetamide 1b reacts via the triplet state to give 3-nitrophenazine 5-oxide 2b.The initial step is addition of the nitro group to the C=O bond.This intermediate 7 rearranges in the ms time scale to yield an O-acylnitro derivative 8.This, in turn, undergoes heterocyclic cleavage (rate dependent upon solvent polarity) and the aminium cation thus formed cyclizes to 2b.Intermediate 7 is sensitive to acid-catalysed hydrolysis, and the cleavage of 8 and subsequent cyclization are influenced by various additives.Thus, with triphenylphosphine a phosphoranylidenamino derivative is obtained, and 2,6-di-tert-butylphenol gives 4-nitro-2-nitrosodiphenylamine.Two other amides are compared.
Enthalpies of combustion of 2,4,6-trimethylbenzonitrile, 2,4,6-trimethylbenzonitrile N-oxide, 2,6-dimethylbenzonitrile, 2,4,6-trimethoxybenzonitrile, and 2,4,6-trimethoxybenzonitrile N-oxide: the dissociation ethalpies of the (N-O) bonds
Acree, W. E.,Tucker, Sheryl A.,Zvaigzne, Anita I.,Meng-Yan, Yang,Pilcher, G.,Ribeiro da Silva, Maria D. M. C.
, p. 31 - 36 (2007/10/02)
The standard (pdeg = 0.1 MPa) molar enthalpies of combustion at 298.15 K were measured by static-bomb calorimetry and the standard molar enthalpies of sublimation at 298.15 K were measured by microcalorimetry for the following aromatic nitriles and aromatic nitrile N-oxides: .From the standard molar enthalpies of formation of the gaseous compounds, the molar dissociation enthalpies of the (N-O) bonds were derived: D(N-O)/(kJ*mol-1): trimethylbenzonitrile N-oxide, (222.2 +/- 4.6); trimethoxybenzonitrile N-oxide, (232.8 +/- 3.8).
ELECTROGENERATED CATION RADICALS OF HETEROAROMATIC N-OXIDES AND OXIDATION OF CYCLOHEXANE INDUCED BY THEM
Koldasheva, E. M.,Geletii, Yu. V.,Yanilkin, V. V.,Strelets, V. V.
, p. 886 - 890 (2007/10/02)
The primary products of electrooxidation of heteroaromatic N-oxides are the corresponding cation-radicals.The redox properties of N-oxides, and also the stability of the cation-radicals generated from them, are determined by the number of N atoms and N-oxide groups in the heterocyclic ring and also by the nature of the substituents.Using phenazine di-N-oxide as an example, it was shown that the generation of the cation radical induces the oxidation of cyclohexane into cyclohexanol and cyclohexanone and is accompanied by deoxygenation of the di-N-oxide into a mono-N-oxide.The oxidation of cyclohexane proceeds by two paths, in one of which molecular oxygen participates, while in the second path an oxygen transfer probably takes place from the di-N-oxide cation radical to cyclohexane.
THE REACTION OF QUINOXALINE- AND PHENAZINE-N-OXIDES WITH THIONYL CHLORIDE AND PARATOLUENESULFONYL CHLORIDE
Nasielski, J.,Heilporn, S.,Chauveheid, E.,Poppe, K.,Nasielski-Hinkens, R.
, p. 783 - 788 (2007/10/02)
2,3-Diphenylquinoxaline-N-oxide 1 with thionyl chloride gives only 5-chloro- and 6-chloroquinoxaline and very little deoxygenation.Phenazine-N5-oxide 2, in the same conditions, gives mainly 2-chlorophenazine and minor amounts of 1-chlorophenazine, but here deoxygenation is an important pathway.Freshly recrystallized para-toluenesulfonyl chloride gives a high chlorination-to-tosyloxylation ratio.All these results point to a variable ability of acid chlorides to yield homocycle chlorination or acyloxylation; this is confirmed by the observation that phenazine-N5-oxide and phosphoryl chloride give fair amounts of aryl phosphate.
ELECTROCHEMICAL REDUCTION OF 2,2'-DINITRODIPHENYL ETHER AND 2,2'-DINITRODIPHENYLAMINE AT MERCURY CATHODES
Hlavaty, Jaromir,Volke, Jiri,Bakos, Viktor
, p. 379 - 393 (2007/10/02)
2,2'-Dinitrodiphenyl ether (I) is reduced at less negative potentials than 2,2'-dinitrodiphenylamine (II); the respective mechanisms of their reduction differ essentially. (I) is electrolytically reduced in a single wave with an uptake of eight electrons per molecule, giving rise to a bishydroxylamine intermediate which undergoes an intramolecular disproportionation.The resulting 2-nitroso-2'-amino-diphenyl ether undergoes a chemical follow-up reaction leading on the one hand to dibenzo--(1,4,5)-oxadiazepine, on the other hand to a diphenylamine product (resulting by a chemical rearrangement) which reacts with reductants present in the solution and yields dihydrophenazine.It is merely by chance that in the electrolytical reduction of II dihydrophenazine also results in addition to other products. 2,2'-dinitrodiphenylamine (II) enables here, however, a partial electrolytical reduction in which 2-amino-2'-nitrodiphenylamine is formed in a single 6-electron wave.In the following, more negative wave, is clearly separated only in alkaline media, the other nitro group reduces with an uptake of 4 electrons to an intermediate which eliminates the hydroxylamine group with the corresponding electron pair.The subsequent chemical reaction leads to dihydrophenazine.This substance is the reduced form of an chemically and electrochemically reversible system, this system participates in the chemical reaction of reaction intermediates.Its regeneration readily proceeds at potentials more positive than the reduction potential of II.Phenazine is oxidized in the catholyte by the hydroxylamine set free to phenazine N-oxide.Nitrogen is thus eliminated in its elemental form via hydroxylamine from the substrate molecule.
