Types Of Aromatic Amines Research Articles

1-Iodoglycal: A Versatile Intermediate for the Synthesis of d-Glyco Amides and Esters Employing Carbonylative Cross-Coupling Reaction.

In this study, we present the development of two catalytic processes: a Pd-PEPPSI-catalyzed aminocarbonylation and a Pd(OAc)2-Xantphos-catalyzed alkoxycarbonylation of d-glycals, utilizing carbonylative cross-coupling reactions. We explored successfully various types of aromatic amines, as well as alkyl amines and amino acids, to synthesize new d-glycal amides. However, we observed limitations in the reactivity of alkyl and heteroaromatic amines. The processes enabled the synthesis of 20 novel C1-branched glycoamides and 7 new d-gluco esters.

Synthesis of Azo Dyes and Generation of Dot Matrix Using Thin-Layer Chromatography

Thin-layer chromatography, which involves the movement of dyes along a silica-coated plate, is used to observe the progress of chemical reactions and to separate mixtures. We took advantage of this phenomenon to devise a method for generating patterns in the shape of numbers with dots (dot matrix). We prepared the azo dyes necessary for generating the dot matrix and successfully generated dot matrix images of numbers 0 to 9 using three azo dyes synthesized from two types of aromatic amines and three types of phenols. All plates were developed in a hexane:acetone = 5:1 solvent. The advantage of this study is that all azo dyes necessary for drawing can be synthesized from common raw materials. Both the dye synthesis and dot matrix generation can be carried out as part of practical work intended for first-year university students. Alternatively, the experiments could be conducted using the dyes prepared in advance by the instructor, and high school students could be encouraged to consider which dye solution to spot on each lane to draw their desired number by dot matrix.

High-titre production of aromatic amines in metabolically engineered Escherichia coli.

Aromatic amines with diverse physical characteristics are often employed as antioxidants and precursors to pharmaceutical products. As the traditional chemical methods pose serious environmental pollution, there is an arising interest in biomanufacturing aromatic amines from renewable feedstocks. We report the establishment of a bacterial platform for synthesizing three types of aromatic amines, namely, tyramine, dopamine and phenylethylamine. First, we expressed aromatic amino acid decarboxylase from Enterococcus faecium (pheDC) in an Escherichia coli strain with increasing shikimate (SHK) pathway flux towards L-tyrosine. We found that glycerol served as a better carbon source than glucose, resulting in 940 ± 46 mg/L tyramine from 4% glycerol. Next, the genes of lactate dehydrogenase (ldhA), pyruvate formate lyase (pflB), phosphate acetyltransferase (pta) and alcohol dehydrogenase (adhE) were deleted to mitigate the fermentation by-product formation. The tyramine level was further increased to 1.965 ± 0.205 g/L in the shake flask, which was improved by 2.1 times compared with that of the parental strain. By using a similar strategy, we also managed to produce 703 ± 21 mg/L dopamine and 555 ± 50 mg/L phenethylamine. We demonstrated that the knockout of ldhA-pflB-pta-adhE is an effective strategy for improving aromatic amine productions. This study achieved the highest aromatic amine titres in E. coli under shake flask reported to date.

REDUCING THE AGGREGATIVE STABILITY OF EMULSION STYRENE BUTADIENE RUBBER WITH THE USE OF AROMATIC AMINES

In this paper, for the first time, a study was conducted on the use of various types of aro-matic amines in the production of emulsion rubbers to reduce the aggregative stability of latex dispersions. The use of aromatic hydrocarbons containing amine groupsin the technology of sep-aration of rubber from latex makes it possible to obtain emulsion rubbers at low costs of the coag-ulating agent. It was found that the temperature regime of the coagulation process of the latex system has a significant effect on the consumption of aromatic amines used: the lowest consump-tion was noted when using them to reduce the aggregate stability of latex systems at temperatures not exceeding 20 °C. The consumption of the acidifying agent -15 kg/t of rubber. Low amounts of coagulating agent create good prerequisites for the implementation of a closed technological cycle on an industrial scale, reducing water consumption by rubber extraction workshops from latex, which ultimately increases the environmental friendliness of the entire technological process of their production. The analysis of rubbers as well as the physical and mechanical characteristics of vulcanizates prepared on their basis, showed that the main properties of rubber-technical products, from control and experimental samplescomply with the regulatory requirements of GOST and TU.

Chemical coagulation and sonolysis for total aromatic amines removal from anaerobically pre-treated textile wastewater: A comparative study

The present study primarily focuses on the evaluation of the comparative effect of chemical coagulation and ultrasonication for elimination of aromatic amines (AAs) present in anaerobically pretreated textile wastewater containing different types of dyes including azo dyes. Color and COD reduction was also monitored at the optimized conditions. The production of AAs was measured spectrophotometrically in the form of total aromatic amines (TAAs) and also verified with high performance liquid chromatography (HPLC) selectively. A composite coagulant, magnesium chloride (MC) aided with aluminium chlorohydrate (ACH) in an equal ratio (MC + ACH) was utilized during the coagulation process, which yielded 31% of TAAs removal along with 85% of color and 52% of COD reduction. At optimized power (200 W) and sonication time (5 h), an appreciable TAAs degradation efficiency (85%) was observed along with 51% color reduction and 62% COD removal using ultrasonication. The chromatographic data indicate that sulphanilic acid and benzidine types of aromatic amines were produced after the reductive cleavage of utilized textile dyes, which were effectively mineralized after ultrasonication. The degradation followed the first order kinetics with a correlation coefficient (R 2 ) of 0.89 and a first-order kinetic constant (k) of 0.0073 min -1 .