scholarly journals Characterization of Sulfur Compounds in MTBE

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Mingqing Wu ◽  
Chunyan Chang ◽  
Tao Li ◽  
Jian Zhou ◽  
Liping Zhao
Keyword(s):  
Sulfur Atom ◽  
Heterocyclic Compounds ◽  
Elemental Sulfur ◽  
Sulfur Compounds ◽  
Total Carbon ◽  
Formation Mechanisms ◽  
Dimethyl Trisulfide ◽  
Methyl Sulfide ◽  
Chemical Constitution

A study is carried out on chemical constitution of sulfur compounds in MTBE and their formation mechanisms. These sulfur compounds are classified into three types: common sulfur compounds, newly formed sulfur compounds, and high boiling sulfur compounds. Common sulfur compounds which include mercaptans, low molecule sulfides and disulfides, are directly from C4, one of the stocks for production of MTBE. The newly formed sulfur compounds, with one sulfur atom and five or more total carbon atoms in one molecule, are mainly tert-butyl methyl sulfide and tert-butyl ethyl sulfide, thioetherification products of thiols with butenes. Many high boiling sulfur compounds, including polysulfides such as dimethyl trisulfide, multisulfur heterocyclic compounds such as 3,5-dimethyl-1,2,4-trithiolane, and oxygen-containing sulfur compounds such as 2-methoxy-3-methylthio-butane, are also found newly formed in the processes of LPG refining and succedent etherification reaction for producing MTBE. Polysulfides are additional products of elemental sulfur to disulfides, and other high boiling sulfur compounds may be formed by thiols reacting with dienes.

Synthesis and Characterization of Some New Esters Containing Heterocyclic and Derived From Azo Dyes

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami
Keyword(s):  
Schiff Base ◽  
13C Nmr ◽  
Azo Dyes ◽  
Spectral Methods ◽  
Anthranilic Acid ◽  
Heterocyclic Compounds ◽  
Synthesis And Characterization ◽  
Cooh Group ◽  
Molecular Weights

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.

Clinical and molecular cytogenetic characterization of two cases of inverted duplication deletion 8p

2020 ◽  
pp. 41-42
Author(s):  
Д.А. Юрченко ◽  
М.Е. Миньженкова ◽  
Е.Л. Дадали ◽  
Н.В. Шилова
Keyword(s):  
Mental Retardation ◽  
Congenital Heart ◽  
Heart Defects ◽  
Clinical Manifestations ◽  
Formation Mechanisms ◽  
Agenesis Of Corpus Callosum ◽  
Molecular Cytogenetic ◽  
Inverted Duplication ◽  
Cytogenetic Characterization

Синдром инвертированной дупликации короткого плеча хромосомы 8 со смежной терминальной делециенй (inv dup del(8p), ORPHA 96092) - редкая хромосомная аномалия (ХА) с частотой 1/10000-1/30000 живорожденных. В статье представлены клинические и молекулярно-цитогенетические характеристики двух неродственных пациентов с синдромом inv dup del(8p) и уточнены механизмы формирования хромосомного дисбаланса. Inverted duplication deletion 8p syndrome (inv dup del(8p), ORPHA 96092) is a rare chromosomal abnormality with a frequency of 1:10,000 - 30,000 newborns. Clinical manifestations of this syndrome include mental retardation, facial anomalies, hypoplasia/agenesis of corpus callosum, scoliosis and/or kyphosis, hypotonia, congenital heart defects. The article presents the clinical and molecular cytogenetic characteristics of two patients with inv dup del (8p) syndrome and clarifies the formation mechanisms.

Ultrasound-assisted oxidative desulfurization of Arabian extra light oil (AXL) with molecular characterization of the sulfur compounds

Fuel ◽  
2021 ◽  
Vol 305 ◽  
pp. 121612
Author(s):  
Jiyuan Fan ◽  
Aiping Chen ◽  
Saumitra Saxena ◽  
Sundaramurthy Vedachalam ◽  
Ajay K. Dalai ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Oxidative Desulfurization ◽  
Sulfur Compounds ◽  
Light Oil ◽  
Ultrasound Assisted

Identification, Characterization, and Quantification of Impurities of Safinamide Mesilate: Process-Related Impurities and Degradation Products

2017 ◽  
Vol 100 (4) ◽  
pp. 1029-1037 ◽  
Author(s):  
Liang Zou ◽  
Lili Sun ◽  
Hui Zhang ◽  
Wenkai Hui ◽  
Qiaogen Zou ◽  
...  
Keyword(s):  
Degradation Products ◽  
Hplc Method ◽  
Formation Mechanisms ◽  
Stability Indicating ◽  
Related Impurities ◽  
Related Substances ◽  
Water Ph ◽  
Bulk Drug ◽  
First Time

Abstract The characterization of process-related impurities and degradation products of safinamide mesilate (SAFM) in bulk drug and a stability-indicating HPLC method for the separation and quantification of all the impurities were investigated. Four process-related impurities (Imp-B, Imp-C, Imp-D, and Imp-E) were found in the SAFM bulk drug. Five degradation products (Imp-A, Imp-C, Imp-D, Imp-E, and Imp-F) were observed in SAFM under oxidative conditions. Imp-C, Imp-D, and Imp-E were also degradation products and process-related impurities. Remarkably, one new compound, identified as (S)-2-[4-(3-fluoro-benzyloxy) benzamido] propanamide (i.e., Imp-D), is being reported here as an impurity for the first time. Furthermore, the structures of the aforementioned impurities were characterized and confirmed via IR, NMR, and MS techniques, and the most probable formation mechanisms of all impurities proposed according to the synthesis route. Optimum separation was achieved on an Inertsil ODS-3 column (250 × 4.6 mm, 5 μm), using 0.1% formic acid in water (pH adjusted to 5.0) and acetonitrile as the mobile phase in gradient mode. The proposed method was found to be stability-indicating, precise, linear, accurate, sensitive, and robust for the quantitation of SAFM and its process-related substances, including its degradation products.

Characterization of malodorous sulfur compounds in landfill gas

2005 ◽  
Vol 39 (6) ◽  
pp. 1103-1112 ◽  
Author(s):  
Ki-Hyun Kim ◽  
YJ Choi ◽  
EC Jeon ◽  
Young Sunwoo
Keyword(s):  
Landfill Gas ◽  
Sulfur Compounds

Characterization of columns grown during KrF laser micromachining of Al2O3–TiC ceramics

2003 ◽  
Vol 18 (5) ◽  
pp. 1123-1130 ◽  
Author(s):  
V. Oliveira ◽  
R. Vilar
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Laser Pulses ◽  
Formation Mechanisms ◽  
X Ray ◽  
Reducing Conditions ◽  
Transmission Electron ◽  
Column Formation ◽  
Krf Laser

This paper aims to contribute to the understanding of column formation mechanisms in Al2O3–TiC ceramics micromachined using excimer lasers. Chemical and structural characterization of columns grown in Al2O3–TiC composite processed with 200 KrF laser pulses at 10 J/cm2 was carried out by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction analysis. Fully developed columns consist of a core of unprocessed material surrounded by an outer layer of Al2TiO5, formed in oxidizing conditions, and an inner layer, formed in reducing conditions, composed of TiC and Al3Ti or an AlTi solid solution. Possible mechanisms of column formation are discussed.

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