scholarly journals Synthesis and structure-physicochemical properties relationship of thiophene-substituted bis(5,4-d)thiazoles

2018 ◽  
Vol 17 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Zita Tokárová ◽  
Anna Biathová
Keyword(s):  
Physicochemical Properties ◽  
Organic Solvents ◽  
Synthetic Approach ◽  
Reaction Conditions ◽  
Relationship Of

Abstract Substituted thiophene-2-carbaldehydes 1a-dwere utilized in the synthesis of symmetrically substituted thiazolo[5,4-d]thiazoles 3a-d. Bis(5,4-d)thiazoles with thiophene core at the termini are the most employed in the chemistry of materials but exhibit insufficient solubility in majority of organic solvents with notable impact on the low yields of products. Accordingly, the synthetic approach towards 2,5-dithiophen- 2-yl-thiazolo[5,4-d]thiazole (3a) and its substituted derivatives 3b-d is discussed under the various reaction conditions. Appropriate structural characterisations are included with emphasis on relationship between structure and physicochemical properties highlighting the UV-Vis and fluorescence.

Diversity-Oriented Synthesis via Catalyst-Free Addition of Ketones to [e]-Fused 1H-Pyrrole-2,3-diones

Synthesis ◽  
2018 ◽  
Vol 50 (24) ◽  
pp. 4897-4904 ◽  
Author(s):  
Ekaterina Stepanova ◽  
Andrey Maslivets ◽  
Svetlana Kasatkina ◽  
Maksim Dmitriev
Keyword(s):  
Intramolecular Cyclization ◽  
Aromatic Hydrocarbons ◽  
Michael Addition ◽  
Aldol Reaction ◽  
Synthetic Approach ◽  
Reaction Conditions ◽  
Diversity Oriented Synthesis ◽  
Catalyst Free ◽  
Solvent Free Conditions ◽  
Reaction Proceeds

A facile synthetic approach towards two distinct pyrrole-based heterocyclic scaffolds has been developed by the interaction of 1H-pyrrole-2,3-diones fused at the [e]-side to a 1,4-benzoxazin-2-one or quinoxalin-2(1H)-one moiety with ketones. The described interaction proceeds either as an aldol reaction or as a Michael addition/intramolecular cyclization depending on the reaction conditions. The disclosed aldol reaction proceeds with good diastereoselectivity under catalyst-free conditions when the reaction is carried out in aromatic hydrocarbons. Products of the cascade Michael addition/intramolecular cyclization reaction are predominantly formed under catalyst-free and solvent-free conditions. The proposed strategy provides facile access to pharmaceutically interesting pyrrole-based polyheterocycles.

Hydrodesulfurization of Different Feeds on CoMo/Al2O3 Catalyst Prepared Using Cobalt Heteropolyoxomolybdate

2008 ◽  
Vol 73 (8-9) ◽  
pp. 983-999 ◽  
Author(s):  
Alla Spojakina ◽  
Květuše Jirátová ◽  
Václav Novák ◽  
Radostina Palcheva ◽  
Luděk Kaluža
Keyword(s):  
Physicochemical Properties ◽  
Gas Oil ◽  
Reaction Conditions ◽  
Alumina Support ◽  
Hds Catalysts ◽  
Light Gas Oil ◽  
Al2o3 Catalyst

CoMo/Al2O3 catalyst prepared by impregnation of alumina support with cobalt heteropolyoxomolybdate was tested in hydrodesulfurization (HDS) of thiophene, 1-benzothiophene, or light gas oil under various reaction conditions and reactor arrangements. Its physicochemical properties are also examined. The obtained data are compared with those of two industrial HDS catalysts.

scholarly journals The Relationship of Liver Function Tests to Mixed Exposure to Lead and Organic Solvents

2013 ◽  
Vol 25 (1) ◽  
pp. 5 ◽  
Author(s):  
Won-Joon Chang ◽  
Kyu-Tak Joe ◽  
Hye-Young Park ◽  
Jong-Do Jeong ◽  
Duk-Hee Lee
Keyword(s):  
Liver Function ◽  
Organic Solvents ◽  
Liver Function Tests ◽  
Function Tests ◽  
Relationship Of ◽  
The Relationship ◽  
Mixed Exposure

The Effect of Non-enzymatic Glycosylation on the Physicochemical Properties and Immunoreactivity of Chicken Egg Ovomucoid

2020 ◽  
Author(s):  
Miciñski Bartosz ◽  
Lyayla K. Bupebayeva ◽  
Miciñski Jan ◽  
Milewski Stanisław
Keyword(s):  
Physicochemical Properties ◽  
Nutritional Value ◽  
Polyclonal Antibodies ◽  
Antibacterial Properties ◽  
Molecular Techniques ◽  
Reaction Conditions ◽  
Microbial Enzymes ◽  
Chicken Egg ◽  
The World ◽  
Enzymatic Glycosylation

Background: Research studies conducted with the involvement of various molecular techniques have demonstrated that ovomucoid, a protein found in chicken egg whites, is also a major food allergen. Many studies have shown that about 40% of patients with allergy against egg proteins were sensitive to ovomucoid. Egg whites are popularly used in the world to enhance the nutritional value of food products (as additives in pastry, meats, sauces, salads and creams) and the production and use of eggs in the world is increasing. Their complete elimination from the diet is highly challenging. Ovomucoid comprises 186 amino acids and has antibacterial properties, and inhibits the activity of microbial enzymes. In this experiment, chicken egg ovomucoid was isolated and polyclonal antibodies were obtained by immunizing a rabbit with the ovomucoid solution to analyze the effect of non-enzymatic glycosylation on the physicochemical properties and immunoreactivity of the studied ovomucoid. Methods: The study analyzed ovomucoid – a protein isolated from the whites of the analyzed eggs. Ovomucoid was isolated by the method proposed by Roy et al. (2003). The next procedure was rabbit immunization. Polyclonal antibodies were obtained by subcutaneously immunizing a male rabbit with a solution of chicken egg glycated or native (a 100 ìg protein dose) in 1 ml PBS with pH 7.2. All measurements were performed in triplicate. The Fisher’s test was conducted to analyze variations in immunoreactivity and changes in glycation degree. Result: Research has shown that it is needed to research the toxicity of proteins, in this case ovomucoid. Glycation may be recommended as a way to reduce or inhibit immunoreactivity. In case of allergies, such action is necessary and purposeful and it is essential to choose such reaction conditions which do not cause products harmful to human’s health.

scholarly journals Straightforward Strategies for the Preparation of NH-Sulfox­imines: A Serendipitous Story

Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2525-2538 ◽  
Author(s):  
James Bull ◽  
Renzo Luisi ◽  
Leonardo Degennaro
Keyword(s):  
Transition Metal ◽  
Physicochemical Properties ◽  
Direct Synthesis ◽  
Transition Metal Catalysts ◽  
Hypervalent Iodine ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free ◽  
Recent Developments ◽  
New Procedures

Sulfoximines are emerging as valuable new isosteres for use in medicinal chemistry, with the potential to modulate physicochemical properties. Recent developments in synthetic strategies have made the unprotected ‘free’ NH-sulfoximine group more readily available, facilitating further study. This account reviews approaches to NH-sulfoximines, with a focus on our contribution to the field. Starting from the development of catalytic strategies involving transition metals, more sustainable metal-free processes have been discovered. In particular, the use of hypervalent iodine reagents to mediate NH-transfer to sulfoxides is described, along with an assessment of the substrate scope. Furthermore, a one-pot strategy to convert sulfides directly into NH-sulfoximines is discussed, with N- and O-transfer occurring under the reaction conditions. Mechanistic evidence for the new procedures is included as well as relevant synthetic applications that further exemplify the potential of these approaches.1 Introduction2 Strategies to Form NH-Sulfoximines Involving Transition-Metal Catalysts3 Metal-Free Strategies to Prepare NH-Sulfoximines4 Mechanistic Evidence for the Direct Synthesis of NH-Sulfoximines from Sulfoxides and Sulfides5 Further Applications6 Conclusion

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