scholarly journals Approaches to the Synthesis of Dicarboxylic Derivatives of Bis(pyrazol-1-yl)alkanes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 413
Author(s):  
Nikita P. Burlutskiy ◽  
Andrei S. Potapov

Carboxylation of bis(pyrazol-1-yl)alkanes by oxalyl chloride was studied. It was found that 4,4′-dicarboxylic derivatives of substrates with electron-donating methyl groups and short linkers (from one to three methylene groups) can be prepared using this method. Longer linkers lead to significantly lower product yields, which is probably due to instability of the intermediate acid chlorides that are initially formed in the reaction with oxalyl chloride. Thus, bis(pyrazol-1-yl)methane gave only monocarboxylic derivative even with a large excess of oxalyl chloride and prolonged reaction duration. An alternative approach involves the reaction of ethyl 4-pyrazolecarboxylates with dibromoalkanes in a superbasic medium (potassium hydroxide–dimethyl sulfoxide) and is suitable for the preparation of bis(4-carboxypyrazol-1-yl)alkanes with both short and long linkers independent of substitution in positions 3 and 5 of pyrazole rings. The obtained dicarboxylic acids are interesting as potential building blocks for metal-organic frameworks.

Author(s):  
Zhanna V. Chirkova

The basic synthetic methods for obtaining N-hydroxyindoles were studied. The first method is intramolecular reductive cyclization of ortho-substituted nitroaromatic compounds by various reducing agents. Nitrophenyl acetaldehydes (synthesis by Acheson), N,N-disubstituted amino-2-nitrostyrenes (synthesis by Somei), ortho-nitroketoetheres of different structure or 1-(o-nitroarene)-1-cyanoalkylnitroketones, ortho-nitrophenylacetonitriles were used as substrates for the synthesis of N-hydroxyindoles. Titanium chloride (III), zinc in THF solution of ammonium chloride or in acetic acid, stannous chloride in ethanolic HCl, and hydrogen with application of catalytic agent on basis of noble metals (platinum, palladium) were used as reduction agents. The second method is a [3+2]-cycloaddition with nitrozoaromatic compounds to alkynes or deoxygenation ortho-nitro substituted aromatic compounds with subsequent intramolecular cyclization. The third method is catalytic oxidation of 2,3-dihydroindoles or different indoles by concentrated hydrogen peroxide with application of of tungstate sodium as catalyst. We attended special attention to synthesis of functional derivatives of N-hydroxyindole-5,6-dicarboxylic acids because these compounds were synthesized from commercially available basic materials using well known synthetic methods and without using expensive catalysts. Indoles of various designs were synthesized. They may be building blocks for the synthesis of biologically active substances, phthalocyanines of different structures having mesomorphic and catalytic properties. Compounds of this class of heterocycles were found among many natural products and they can be used as therapeutic agents, for example, as inhibitors of human lactate dehydrogenase of isoforms 5, selective inhibitors of monoamine oxidase A and B, and N-methoxyindole can be used to treat breast cancer. For citation:Chirkova Zh.V. Synthesis of N-hydroxyindoles. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 4-20.


Author(s):  
Philip Isett

This chapter deals with the coarse scale velocity. It begins the proof of Lemma (10.1) by choosing a double mollification for the velocity field. Here ∈ᵥ is taken to be as large as possible so that higher derivatives of velement are less costly, and each vsubscript Element has frequency smaller than λ‎ so elementv⁻¹ must be smaller than λ‎ in order of magnitude. Each derivative of vsubscript Element up to order L costs a factor of Ξ‎. The chapter proceeds by describing the basic building blocks of the construction, the choice of elementv and the parametrix expansion for the divergence equation.


2019 ◽  
Vol 16 (7) ◽  
pp. 653-688 ◽  
Author(s):  
Leena Kumari ◽  
Salahuddin ◽  
Avijit Mazumder ◽  
Daman Pandey ◽  
Mohammad Shahar Yar ◽  
...  

Heterocyclic compounds are well known for their different biological activity. The heterocyclic analogs are the building blocks for synthesis of the pharmaceutical active compounds in the organic chemistry. These derivatives show various type of biological activity like anticancer, antiinflammatory, anti-microbial, anti-convulsant, anti-malarial, anti-hypertensive, etc. From the last decade research showed that the quinoline analogs plays a vital role in the development of newer medicinal active compounds for treating various type of disease. Quinoline reported for their antiviral, anticancer, anti-microbial and anti-inflammatory activity. This review will summarize the various synthetic approaches for synthesis of quinoline derivatives and to check their biological activity. Derivatives of quinoline moiety plays very important role in the development of various types of newer drugs and it can be used as lead compounds for future investigation in the field of drug discovery process.


2021 ◽  
Author(s):  
Anurag Mukherjee ◽  
Suhrit Ghosh

Naphthalene-diimide (NDI) derived building blocks have been explored extensively for supramolecular assembly as they exhibit attractive photophysical properties, suitable for applications in organic optoelectronics. Core-substituted derivatives of the NDI chromophore (cNDI) differ significantly from the parent NDI dye in terms of optical and redox properties. Adequate molecular engineering opportunities and substitution-dependent tunable optoelectronic properties make cNDI derivatives highly promising candidates for supramolecular assembly and functional material. This short review discusses recent development in the area of functional supramolecular assemblies based on cNDIs and related molecules.


Polyhedron ◽  
2014 ◽  
Vol 70 ◽  
pp. 180-187 ◽  
Author(s):  
Peng Du ◽  
Yan Yang ◽  
Ying-Ying Liu ◽  
Yuan-Chun He ◽  
Hong-Mei Zhang ◽  
...  

2014 ◽  
Vol 919-921 ◽  
pp. 2013-2016 ◽  
Author(s):  
Ya Bing Liu ◽  
Hong Jie Wang ◽  
Hong Kai Zhao

A POM - based organice - inorganic hybrid compound with the chemical formula of[Cu (phen)2]3[W6O19] (phen = 1,10-phenanthroline) (1) has been hydrothermally synthesized andstructurally characterized by the elemental analysis, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space groupC2/c witha=18.319(4) Å,b= 17.311(4) Å,c= 22.248(4) Å,β= 112.40(3) o,V= 6523(2) Å3,Z= 4, R1= 0.0448, andwR2=0.1218. Compound 1 consists of the [W6O19]3-building blocks and [Cu (phen)2]+metal organic cationic moieties, which are packed together via the extensive hydrogen-bonding interactions to form a three-dimensional supramolecular framework. The adsorption of methylene blue (MB) under UV irradiation with 1 as the heterogeneous adsorbent has been investigated, showing a good adsorptive property of 1 for MB degradation.


1996 ◽  
Vol 61 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý

New approach to the preparation of steroids with connecting bridge, based on an O-carboxymethyloxime (CMO) structure, and with terminal hydroxy group, is presented. 17-CMO derivatives of 3β-acetoxy- and 3β-methoxymethoxyandrost-5-en-17-one were condensed with α,ω-amino alcohols to give derivatives with a chain of seven to nine atoms. After THP-protection, these compounds were converted to 3-keto-4-ene derivatives. An alternative synthesis consisted in transformation of 17-CMO derivatives with bonded amino acids by reduction of the terminal carboxyl. The resulting compounds were designed as building blocks for the preparation of bis-haptens for sandwich immunoassays.


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