Aromatic diazocompounds. XII. Identification of primary aromatic amines from the absorption spectra of derived azo dyes

1953 ◽  
Vol 18 (5) ◽  
pp. 663-678
Author(s):  
Z. J. Allan ◽  
F. Mužík
Keyword(s):  
Absorption Spectra ◽  
Azo Dyes ◽  
Aromatic Amines ◽  
Primary Aromatic Amines

Analysis of primary aromatic amines originated from azo dyes in commercial textile products in Japan

2010 ◽  
Vol 45 (10) ◽  
pp. 1281-1295 ◽  
Author(s):  
Tsuyoshi Kawakami ◽  
Kazuo Isama ◽  
Harunobu Nakashima ◽  
Toshie Tsuchiya ◽  
Atsuko Matsuoka
Keyword(s):  
Azo Dyes ◽  
Aromatic Amines ◽  
Primary Aromatic Amines ◽  
Textile Products

scholarly journals Mechanisms and products of azo coupling in histochemical protease procedures based on primary aromatic amines as unspecific moieties.

1990 ◽  
Vol 38 (9) ◽  
pp. 1295-1300 ◽  
Author(s):  
H G Frank
Keyword(s):  
Azo Dyes ◽  
Aromatic Amines ◽  
Elevated Temperatures ◽  
Test Tube ◽  
Aromatic Nucleus ◽  
Diazonium Salts ◽  
Amino Group ◽  
Tissue Sections ◽  
Primary Aromatic Amines ◽  
Methylated Amines

It is presumed that the azo dyes generated by histochemical protease reactions are formed by substitution of a reactive aromatic carbon. They are referred to as dyes of the C-azo series. To confirm this assumption, the absorption spectra between 330 and 630 nm of azo dyes resulting from coupling between various aromatic amines of the aniline and naphthylamine series and the diazonium salts Fast Blue B and Fast Garnet GBC were studied in test tube experiments. Some of the amines were blocked by methylation to prevent coupling either at the amino group (N-methylated) or at the aromatic nucleus (C-methylated). Coupling was performed in buffered aqueous solutions of the diazonium salts. For analysis the azo dyes were dissolved in dimethylformamide. For acid rearrangement these solutions were acidified and incubated at elevated temperatures. After detection of dipeptidyl peptidase IV in tissue sections using Gly-Pro-4-methoxy-2-naphthylamine as substrate, the resulting dye was extracted and compared with the test tube compounds. All aromatic amines yielded azo dyes. Dyes extracted from sections and those test tube compounds derived from unmethylated or C-methylated amines showed almost identical spectral maxima, whereas dyes formed by N-methylated amines yielded different spectra. Acid rearrangement did not influence the spectral maxima of the N-methylated amine-derived dyes. Dyes resulting from C-methylated amines were destroyed. The results indicate that under histochemical conditions diazonium salts react primarily with the liberated free amino group but not with the aromatic nucleus of the unspecific moiety. Therefore, it is proposed that the formula of the final reaction product in naphthylamine-based protease histochemistry should be given as an N-azo dye, e.g., as a triazene.

Treatment of colored textile wastewater in SBR with emphasis on the biodegradation of sulfonated aromatic amines

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
N.D. Lourenço ◽  
J.M. Novais ◽  
H.M. Pinheiro
Keyword(s):  
Azo Dyes ◽  
Aromatic Amines ◽  
Microbial Population ◽  
Textile Wastewater ◽  
Aerobic Biodegradation ◽  
Oxygen Sensitivity ◽  
Anaerobic Conditions ◽  
Textile Effluents ◽  
Primary Aromatic Amines ◽  
Reductive Decolorization

Azo dyes represent a problematic contaminant class in textile effluents because they are normally resistant to aerobic biodegradation and are consequently difficult to eliminate by conventional wastewater treatment systems. Since the mineralization of azo dyes is not likely to occur under the anaerobic conditions generally required for their reductive decolorization, anaerobic/aerobic SBR are promising systems for the decolorization of textile effluents containing azo dyes integrated with the mineralization of the resulting aromatic amines. In the present study, high decolorization yields (up to 90% with an initial dye concentration of 100 mg l-1) of a monoazo dye were achieved in the anaerobic phase of an anaerobic/aerobic SBR. However, the aromatic amines formed were not mineralized in the subsequent aerated phase. The development a bacterial community able to mineralize specific sulfonated aromatic amines was attempted in an aerobic SBR, operated downstream of the anaerobic/aerobic SBR. This attempt was not successful, since the microbial population was able to convert the primary aromatic amines, though not to full mineralization, but resulted in the identification of different chromatographic patterns arising from the bioconversion of azo dye metabolites in different oxygen-availability conditions. Oxygen-sensitivity of the involved intermediates is, however, an interfering factor possibly impairing biodegradation

Catalyst- and solvent-free Csp2-H functionalization of 4-hydroxycoumarins via C-3 dehydrogenative aza-coupling under ball-milling

2021 ◽  
Author(s):  
Goutam Brahmachari ◽  
Indrajit Karmakar ◽  
Pintu Karmakar
Keyword(s):  
Ball Milling ◽  
Aromatic Amines ◽  
Solvent Free ◽  
One Pot ◽  
Biologically Relevant ◽  
Tert Butyl ◽  
Three Component Reaction ◽  
Primary Aromatic Amines

A one-pot procedure for the synthesis of biologically relevant coumarin-hydrazones by a three-component reaction between 4-hydrocoumarins, primary aromatic amines and tert-butyl nitrite under ball-milling in the absence of any catalyst/additive...

scholarly journals Synthesis of Organic Ligands via Reactions of 4-Benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione with N-Nucleophiles

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Hassan Kabirifard ◽  
Pardis Hafez Taghva ◽  
Hossein Teimouri ◽  
Niloofar Koosheshi ◽  
Parastoo Javadpour ◽  
...  
Keyword(s):  
High Temperature ◽  
Carbonyl Group ◽  
Aromatic Amines ◽  
Room Temperature ◽  
Organic Ligands ◽  
Carboxyl Group ◽  
Primary Aromatic Amines

The reaction of 4-benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione (1) with aminoheteroaryls, lamotrigine, 1,3-diaminoheteroaryls, dapsone, NH2R (hydroxylamine, DL-1-phenylethylamine, and metformin), and 4,4′-bipyridine in THF/H2O (1 : 1) at room temperature led to 3-N-phenylthiocarbamoyl-2-butenamides 2–5, while that with naphthylamines and 1,3-phenylenediamine in ethanol at high temperature led to 5-phenylamino-2,5-dihydrothiophene-2-ones 6–8 as organic ligands in the medium to good yields. These showed the nucleophilic attacks of N-nucleophiles, except primary aromatic amines, on thioester carboxyl group (C-2) of thiophene-2,3-dione ring 1. However, the nucleophilic attacks of primary aromatic amines on the carbonyl group (C-3) of thiophene-2,3-dione 1 occurred in the form of substituted thiophenes.

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