scholarly journals Approaches towards the synthesis of 5-aminopyrazoles

2011 ◽  
Vol 7 ◽  
pp. 179-197 ◽  
Author(s):  
Ranjana Aggarwal ◽  
Vinod Kumar ◽  
Rajiv Kumar ◽  
Shiv P Singh

The biological and medicinal properties of 5-aminopyrazoles have prompted enormous research aimed at developing synthetic routes to these heterocyles. This review focuses on the biological properties associated with this system. Various synthetic methods developed up to 2010 for these compounds are described, particularly those that involve the reactions of β-ketonitriles, malononitrile, alkylidenemalononitriles and their derivatives with hydrazines, as well as some novel miscellaneous methods.

2020 ◽  
Vol 24 (24) ◽  
pp. 2823-2844
Author(s):  
Aditya Bhattacharyya

: Multiheteroatom-containing small-sized cyclic molecules such as 2- iminothiazolidines are often found to possess beneficial pharmacological properties. In this review article, the biological significance of 2-iminothiazolidines is discussed and the literature reports published in the last 15 years spanning from 2006 to 2020 describing various preparative routes to access 2-iminothiazolidine derivatives have been categorically and chronologically described. The notable synthetic methods discussed here involve ringexpansion transformations of nonactivated and activated aziridines, thiiranes, epoxides, and other miscellaneous reactions.


2020 ◽  
Vol 24 (8) ◽  
pp. 817-854
Author(s):  
Anil Kumar ◽  
Nishtha Saxena ◽  
Arti Mehrotra ◽  
Nivedita Srivastava

Quinolone derivatives have attracted considerable attention due to their medicinal properties. This review covers many synthetic routes of quinolones preparation with their antibacterial properties. Detailed study with structure-activity relationship among quinolone derivatives will be helpful in designing new drugs in this field.


2019 ◽  
Vol 19 (17) ◽  
pp. 1392-1406
Author(s):  
Suvarna G. Kini ◽  
Ekta Rathi ◽  
Avinash Kumar ◽  
Varadaraj Bhat

Diphenyl ethers (DPE) and its analogs have exhibited excellent potential for therapeutic and industrial applications. Since the 19th century, intensive research is perpetuating on the synthetic routes and biological properties of DPEs. Few well-known DPEs are Nimesulide, Fenclofenac, Triclosan, Sorafenib, MK-4965, and MK-1439 which have shown the potential of this moiety as a lead scaffold for different pharmacological properties. In this review, we recapitulate the diverse synthetic route of DPE moiety inclusive of merits and demerits over the classical synthetic route and how this moiety sparked an interest in researchers to discern the SAR (Structure Activity Relationship) for the development of diversified biological properties of DPEs such as antimicrobial, antifungal, antiinflammatory & antiviral activities.


2021 ◽  
Author(s):  
◽  
Michael Meijlink

<p>Azasugars [e.g., 1-deoxy-aza-xylopyranose (1) Figure 1] are structural analogues of sugars [e.g., α-D-xylopyranose (2)] where the ring oxygen is substituted by a nitrogen atom. The resemblance of azasugars to their carbohydrate counterparts gives them various biological properties, such as the inhibition of glycosidase and glycosyltransferase enzymes, and as such, these compounds have been in clinical trials for the treatment of AIDS, diabetes,and cancer. Synthetic routes to azasugars have often involved the use of protecting groups, and therefore have generally reduced efficiency by requiring additional steps to apply or remove protecting groups or requiring adjustment of stereochemistry during the synthesis. This thesis presents the first example of a synthesis of four sterochemically different piperidine triols through a four-step methodology minimising the use of protecting groups starting from pentoses. The synthesis of D-xylose derived (3R,4r,5S)-piperidine triol was previously obtained in 40% yield over five steps, but was afforded in 45% overall yield over four steps using the methodology described within this thesis. Next, D-ribose derived (3R,4s,5S)-piperidine triol was obtained in 40% overall yield over four steps, which afforded a vast improvement on the previous most efficient synthetic route obtaining the azasugar in 24% yield over four steps. This four-step three-pot methodology has thus allowed for the synthesis of these piperidine triols in overall yields ranging from 4-69%, surpassing previous total syntheses in efficiency and improving overall atom economy. To further probe the applicability of the methodology, N-alkyl analogues (such as butyl-, phenylethyl-, and hydroxyethyl-analogues) of all four different piperidine triols were synthesised in comparable or greater overall yields compared to literature reports without any required adaptation to the original procedure. Included in these N-alkyl analogues are seven novel azasugars which were obtained in overall yields ranging from 6-35%.</p>


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6130
Author(s):  
Fei Liu ◽  
Xueling Hou ◽  
Ben-Lin Hu ◽  
Run-Wei Li

Elastic semiconductors are becoming more and more important to the development of flexible wearable electronic devices, which can be prepared by structural engineering design, blending, and the intrinsic elastification of organic semiconductors (intrinsically elastic organic semiconductor, IEOS). Compared with the elastic semiconductors prepared by structural engineering and blending, the IEOS prepared by organic synthesis has attracted numerous attentions for its solution processability and highly tunable chemical structures. For IEOSs, reasonable designs of synthetic routes and methods are the basis for realizing good mechanical and electrical properties. This brief review begins with a concise introduction of elastic semiconductors, then follows with several synthetic methods of IEOSs, and concludes the characteristics of each method, which provides guidance for the synthesis of IEOSs in the future. Furthermore, the properties of IEOSs are involved from the aspects of electrical, mechanical properties, and the applications of the IEOSs in elastic electronic devices. Finally, the challenge and an outlook which IEOSs are facing are presented in conclusion.


2021 ◽  
Vol 9 ◽  
Author(s):  
Agnieszka Staśkiewicz ◽  
Patrycja Ledwoń ◽  
Paolo Rovero ◽  
Anna Maria Papini ◽  
Rafal Latajka

Peptidomimetics play a fundamental role in drug design due to their preferential properties regarding natural peptides. In particular, compounds possessing nitrogen-containing heterocycles have been intensively studied in recent years. The triazolyl moiety incorporation decreases the molecule susceptibility to enzymatic degradation, reduction, hydrolysis, and oxidation. In fact, peptides containing triazole rings are a typical example of peptidomimetics. They have all the advantages over classic peptides. Both efficient synthetic methods and biological activity make these systems an interesting and promising object of research. Peptide triazole derivatives display a diversity of biological properties and can be obtained via numerous synthetic strategies. In this review, we have highlighted the importance of the triazole-modified peptidomimetics in the field of drug design. We present an overview on new achievements in triazolyl-containing peptidomimetics synthesis and their biological activity as inhibitors of enzymes or against cancer, viruses, bacteria, or fungi. The relevance of above-mentioned compounds was confirmed by their comparison with unmodified peptides.


2017 ◽  
Vol 47 (8) ◽  
Author(s):  
Giuliane Sampaio de Souza ◽  
Oriel Herrera Bonilla ◽  
Eliseu Marlônio Pereira de Lucena ◽  
Yuri Pereira Barbosa

ABSTRACT: Marmeleiros are popularly known for the medicinal properties ascribed to their essential oils. This research aimed to analyze the essential oil of leaves from three Croton species (Croton argyrophylloides, Croton jacobinensis, and Croton sincorensis), to verify whether the daily time and harvest season in the year may interfere with their essential oils performance and composition. From each species, 1,500g of green leaves were harvested in Viçosa do Ceará - CE, at 6am and 12pm, during both dry and rainy seasons. Essential oil extraction was conducted by the method of water vapor drag and chemical profile was analyzed by gas chromatography-mass spectrometry (GC/MS). The highest yield was obtained at 12pm in the dry season for C. argyrophylloides and C. jacobinensis, and at 6am in the rainy season for C. sincorensis. Bicyclogermacrene demonstrated higher relative abundance in C. argyrophylloides (28.09 to 30.59%), C. jacobinensis (25.2 to 30.14%), and C. sincorensis (23.86 and 21.71%), and the only exception was at 6am in C. sincorensis, where (E)-caryophyllene was the most abundant compound (25.34%). The yield and composition of the studied species were influenced by rainfall, temperature, and sunlight, presenting statistical significant differences between the different periods studied. The species produce constituents with specific biological properties; and therefore, they can be used as a natural source.


2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Anuoluwa Abimbola Akinsiku ◽  
Enock Olugbenga Dare ◽  
Kolawole Oluseyi Ajanaku ◽  
Olayinka Oyewale Ajani ◽  
Joseph Adebisi O. Olugbuyiro ◽  
...  

In the quest for environmental remediation which involves eco-friendly synthetic routes, we herein report synthesis and modeling of silver nanoparticles (Ag NPs) and silver/nickel allied bimetallic nanoparticles (Ag/Ni NPs) using plant-extract reduction method. Secondary metabolites in the leaf extract of Canna indica acted as reducing agent. Electronic transitions resulted in emergence of surface plasmon resonance in the regions of 416 nm (Ag NPs) and 421 nm (Ag/Ni NPs) during optical measurements. Further characterizations were done using TEM and EDX. Antimicrobial activity of the nanoparticles against clinical isolates was highly significant as P<0.05. These findings suggest application of Ag NPs as antibacterial agent against E. coli, S. pyogenes, and antifungal agent against C. albicans. Possible antibacterial drugs against S. pyogenes and E. coli can also be designed using Ag/Ni nanohybrid based on their strong inhibition activities. Similarly, the enhanced SPR in the nanoparticles is suggested for applications in optical materials, as good absorbers and scatters of visible light. Theoretical model clarified that the experiment observation on the relationship between metallic nanoparticles penetration through peptidoglycan layers and the activeness of microbial species depends on the nature of the nanoparticles and pore size of the layer.


2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Neha Pandit ◽  
Rajeev K. Singla ◽  
Birendra Shrivastava

Oxazolidinone is a five-member heterocyclic ring exhibiting potential medicinal properties with preferential antibacterial activity. Scientists reported various synthetic procedures for this heterocyclic structure. Current review articles tried to cover each and every potential aspect of oxazolidinone like synthetic routes, pharmacological mechanism of action, medicinal properties, and current research activities.


2018 ◽  
Vol 14 ◽  
pp. 203-242 ◽  
Author(s):  
Ranjana Aggarwal ◽  
Suresh Kumar

The condensation of 5-aminopyrazole with various bielectrophilic moieties results in the formation of pyrazoloazines, an interesting array of fused heterocyclic systems. The development of new synthetic routes towards pyrazoloazines for their biological and medicinal exploration is an attractive area for researchers throughout the world. The present review focuses on various synthetic methods developed in the last decade for the synthesis of differently substituted pyrazoloazines by a broad range of organic reactions by means of 5-aminopyrazole as a precursor.


Sign in / Sign up

Export Citation Format

Share Document