scholarly journals A Facile and Efficient Synthesis of Diaryl Amines or Ethers under Microwave Irradiation at Presence of KF/Al2O3 without Solvent and Their Anti-Fungal Biological Activities against Six Phytopathogens

2013 ◽  
Vol 14 (9) ◽  
pp. 18850-18860 ◽  
Author(s):  
Liang-Zhu Huang ◽  
Pan Han ◽  
You-Qiang Li ◽  
Ying-Meng Xu ◽  
Tao Zhang ◽  
...  
2019 ◽  
Vol 16 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Renu Bala ◽  
Vandana Devi ◽  
Pratibha Singh ◽  
Navjot Kaur ◽  
Pawandeep Kaur ◽  
...  

Background: Tetrahydroindazole, a member of the fused-pyrazole system, is a least studied class of heterocyclic compounds owing to its scarcity in nature. However, a large number of synthetically prepared tetrahydroindazoles are known to show a variety of biological activities such as interleukin- 2 inducible T-Cell kinase inhibitors, AMPA receptor positive allosteric modulators, antitumor, antituberculosis, anti-inflammatory and antimicrobial activities. Vilsmeier-Haack reaction is one of the most important chemical reactions used for formylation of electron rich arenes. Even though Vilsmeier- Haack reaction was studied on a wide variety of hydrazones derived from active methylene compounds, literature lacks the examples of the use of 4-substituted cyclohexanones as a substrate for the synthesis of 4,5,6,7-tetrahydroindazoles. The study of the reaction of Vilsmeier-Haack reagent with hydrazones derived from cyclic keto compounds having active methylene has been considered the interested topic of investigation. In the present study, ethyl cyclohexanone-4-carboxylate was treated with one equivalent of various hydrazines for two hours and the resulted hydrazones were further treated with an OPC-VH reagent (Vilsmeier-Haack reagent isolated from phthaloyl dichloride and N,Ndimethylformamide) afforded 4,5,6,7-tetrahydroindazoles in excellent yields. The synthesized compounds 4a-f and 5a-f were screened for their antioxidant activities using the DPPH radical scavenging assay. The target compounds were synthesized regioselectively using 4+1 approach in excellent yields. A number of experiments using both conventional heating as well as microwave irradiation methods were tried and on comparison, microwave irradiation method was found excellent in terms of easy work up, high chemical yields, shortened reaction times, clean and, no by-products formation. Some of the synthesized compounds showed significant antioxidant activity. The microwave assisted synthesis of 4,5,6,7-tetrahydroindazoles from ethyl cyclohexanone-4-carboxylate has been reported under mild conditions in excellent yield. Easy work up, high chemical yield, shortened reaction times, clean and no by-products formation are the major advantages of this protocol. These advantages may make this method useful for chemists who are interested in developing novel 4,5,6,7-tetrahydroindazole based drugs.


2019 ◽  
Vol 16 (2) ◽  
pp. 258-275 ◽  
Author(s):  
Navjeet Kaur

Background:A wide variety of biological activities are exhibited by N, O and S containing heterocycles and recently, many reports appeared for the synthesis of these heterocycles. The synthesis of heterocycles with the help of metal and non-metal catalyst has become a highly rewarding and important method in organic synthesis. This review article concentrated on the synthesis of S-heterocylces in the presence of metal and non-metal catalyst. The synthesis of five-membered S-heterocycles is described here.Objective:There is a need for the development of rapid, efficient and versatile strategy for the synthesis of heterocyclic rings. Metal, non-metal and organocatalysis involving methods have gained prominence because traditional conditions have disadvantages such as long reaction times, harsh conditions and limited substrate scope.Conclusion:The metal-, non-metal-, and organocatalyst assisted organic synthesis is a highly dynamic research field. For ßthe chemoselective and efficient synthesis of heterocyclic molecules, this protocol has emerged as a powerful route. Various methodologies in the past few years have been pointed out to pursue more sustainable, efficient and environmentally benign procedures and products. Among these processes, the development of new protocols (catalysis), which avoided the use of toxic reagents, are the focus of intense research.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
C Nirmala ◽  
M Sridevi

Abstract Background In modern therapeutics, various human pathological disturbances were treated with the plant-based products. Waltheria indica Linn, a perennial herb, was commonly used in traditional medicine worldwide against various ailments such as cough, dysentery, diarrhea, bladder disorder, hemoptysis, inflammations, neuralgia, wounds, and ulcers. Main body The shrub was majorly distributed in tropical, subtropical regions and exists in many distinct local forms. Both the crude extracts and purified compounds from the whole plant and its parts showed wide pharmacological properties like antioxidant, analgesic, sedative, anti-bacterial, anti-fungal, and anti-parasitic. The phytochemical profile and traditional usage highlight the potency of the plant in the treatment of microbial infections and inflammatory diseases. Yet, additional studies are required for the confirmations of its traditional uses against other diseases. More detailed understanding of anti-cataract, anti-diabetics, asthma, anemia, and anti-cancer mechanism has to be explored. Though many research articles on the proposed plant are available, there has been a rising concern in the therapeutic property, especially on the alkaloids and flavonoids from this plant for drug design. Conclusion This article aims in a systematic and updated review on distribution, botany, traditional uses, phytocompounds, and relevant biological activities from each part of the plant. The information was collected from databases like PubMed, ScienceDirect, Web of Science, Google Scholar, books, dissertation, and reports via academic libraries that included more than 100 articles published since 1937. This ethnopharmacological study of the plant may create new insight into drug discovery to develop important novel leads against various biological targets.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Dalila Meziane ◽  
Abdelhamid Elias ◽  
Erwann Guénin

The aim of this investigation was to develop an efficient, rapid, and selective method for the synthesis ofω-alkylenediphosphoric acids (HO)2(O)P-O-CH2n-O-P(O)(OH)2from reaction of several diols with phosphorus oxychloride. The reaction was investigated using three methodologies: (i) presence of a base, (ii) classical heating, and (iii) use of microwave irradiation. Influence of reaction temperature and molar ratio of reagents, as well as the nature of the solvent, was studied using these three different methods.


ChemInform ◽  
2008 ◽  
Vol 39 (29) ◽  
Author(s):  
Qingqing Shao ◽  
Shujiang Tu ◽  
Chunmei Li ◽  
Longji Cao ◽  
Dianxiang Zhou ◽  
...  

ChemInform ◽  
2009 ◽  
Vol 40 (17) ◽  
Author(s):  
Jian-Feng Zhou ◽  
Gui-Xia Gong ◽  
Li-Tao An ◽  
Yu Liu ◽  
Feng-Xia Zhu ◽  
...  

Author(s):  
Iqra Sarfraz ◽  
Azhar Rasul ◽  
Ghulam Hussain ◽  
Muhammad Ajmal Shah ◽  
Bushra Nageen ◽  
...  

: Oxalis corniculata (Oxalidaceae) is a small decumbent and delicate appearing medicinal herb flourishing in warm temperate and tropical domains such as Pakistan and India. Main bioactive chemical constituents of Oxalis plant include several alkaloids, flavonoids, terpenoids, cardiac glycosides, saponins, phlobatannins along with steroids. Due to its polyphenolic, glycosides and flavonoid profile, it is proved to be protective in numerous ailments and exhibit various biological activities such as anti-fungal, anti-cancer, anti-oxidant, anti-bacterial, anti-diabetic, and cardioprotective. Moreover, bioactive phytochemicals from this plant possess significant wound healing potential. Our current effort intends to emphasize on the immense significance of this plant species, which have not been the subject matter of clinical trials and effective pharmacological studies, even though its favored usage has been stated. This review proposes that Oxalis corniculata possess potential for the cure of various diseases, however, further researches on isolation and characterization of bioactive compounds along with pre-clinical trials are compulsory to figure out its pharmacological applications.


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