scholarly journals Easy, Simplistic and Green Synthesis of Various Benzimidazole and Benzoxazole Derivatives Using PEG400 as a Green Solvent

Author(s):  
Mita D. Khunt ◽  
Vipul C. Kotadiya ◽  
Denish J. Viradiya ◽  
Bharat H. Baria ◽  
Umed C. Bhoya

An improved environmentally benign procedure for the synthesis of various benzimidazole and benzoxazole derivatives using green solvent PEG400. We have optimized the reaction condition and it was found that PEG400 was believed to be best as compared to PEG200, PEG600 and PEG800 at 80 to 85 °C. This method provides a novel route for the synthesis of benzimidazole and benzoxazole derivatives. The main attractive features of this process are a mild reaction conditions, easy workup procedure and good to excellent yield. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis.

2005 ◽  
Vol 09 (06) ◽  
pp. 430-435 ◽  
Author(s):  
Can-Cheng Guo ◽  
Tie-Gang Ren ◽  
Jian Wang ◽  
Chun-Yan Li ◽  
Jian-Xin Song

Five new meso-tetrakis(1-arylpyrazol-4-yl)porphyrins were synthesized to investigate their fluorescence properties. Preparation of these porphyrins was carried out by cyclization of tetramethoxypropane with substituted phenylhydrazine, followed by formylation to give the corresponding aldehydes, which reacted with pyrrole under the Adler reaction condition to get the target porphyrins (1a-1e). All the porphyrins were characterized by 1 H NMR, elemental analysis, UV-vis spectra and mass spectra. Red fluorescence emission of these porphyrins was observed in fluorescence spectra. Compared with meso-tetraphenylporphyrin (TPPH2), these meso-tetrakis(1-arylpyrazol-4-yl) porphyrins had a significant red shift in UV-vis and fluorescence spectra with increased fluorescence quantum yields.


2013 ◽  
Vol 2013 ◽  
pp. 1-23 ◽  
Author(s):  
Kanagarajan Hemalatha ◽  
Gunabalan Madhumitha ◽  
Amir Kajbafvala ◽  
Narayanan Anupama ◽  
Rajesh Sompalle ◽  
...  

Heterocyclic motif is an important scaffold which has both industrial and pharmaceutical applications. These motifs can be prepared using wide variety of reaction conditions such as the use of expensive catalyst, toxic solvent, harsh reaction condition like the use of base, high temperature, and multistep reaction. Although various methods are involved, the chemistry arena is now shifted towards the greener way of synthesis. Nanocatalyst constitutes an important role in the green synthesis. This is because the activity of the catalyst resides in the exposed portion of the particles. By decreasing the size of the catalyst, advantages such as more surface area would be exposed to the reactant, only negligible amount would be required to give the significant result and selectivity could be achieved, thereby, eliminating the undesired products. The current review enlists the various types of nanocatalyst involved in the heterocyclic ring formation and also some other important functionalization over the ring.


2019 ◽  
Vol 6 (1) ◽  
pp. 62-68
Author(s):  
Km Neha Shivhare ◽  
Anushree Srivastava ◽  
Ibadur Rahman Siddiqui

We describe herein the use of glycerol as an efficient and sustainable approach for the synthesis of 2-amino-1, 8-naphthyridine-3-carbonitriles and 2-amino-3-quinolinecarbonitriles. The catalyst- free reactions occur straightforwardly using biodegradable and non-hazardous solvent. It is a strategy to address mounting environmental concerns with current approach includes the use of environmentally benign solvent, simple workup procedure, economic viability, shorter reaction time and providing good to excellent yield.


2019 ◽  
Vol 4 (2) ◽  
pp. 109-112
Author(s):  
Mujahed Shaikh ◽  
Ashvini Sonone ◽  
Mazahar Farooqui ◽  
Ayesha Durrani

A green and environmentally benign protocol is developed for the synthesis of Schiff bases of sulphur containing compound by irradiating thiazole and pyrazole aldehyde in glycerol under microwave irradiation at 70 ºC with trimethylsilyl chloride (TMSCl) as a catalyst. The method has advantages such as excellent yield, use of green solvent, easy work-up and most important the reaction completed within 2.5 min by using TMSCl catalyst. The TMSCl is an acidic catalyst, which enhances the yield of product, reaction time (with microwave, with reflux at 75 ºC and with stirring at room temperature) which can be easily removed from reaction mask.


Author(s):  
Anil R. Morabia ◽  
Yogesh T. Naliapara

A series of novel 5-(2-bromophenyl)-N-cyclohexyl-2-(methylthio)-6-nitro-7-phenyl-4,7-dihydropyrazolo [1,5-a] pyrimidine-3-carboxamides were synthesized by a one-pot reaction of 5-amino-N-cyclohexyl-3-(methylthio)-1H-pyrazole-4-carboxamide, 1-(2-bromophenyl)-2-nitroethanone and aryl aldehydes in the presence of boric acid in water at refluxing temperature. Structures of compounds were demonstrated by Fourier transform infrared, 1H NMR, 13C NMR and elemental analysis. The advantages of this method are mild reaction condition, good yields, and operational simplicity.


2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.


1995 ◽  
Vol 60 (7) ◽  
pp. 1236-1241 ◽  
Author(s):  
Martin Doležal ◽  
Jiří Hartl ◽  
Antonín Lyčka ◽  
Vladimír Buchta ◽  
Želmíra Odlerová

Nucleophilic substitution of 3-chloro-5-cyano-2-pyrazinecarboxamide by substituted anilines afforded substituted 3-arylamino-5-cyano-2-pyrazinecarboxamides I-X. The structures of compounds were confirmed by elemental analysis, UV, IR and 1H NMR spectra. The assessment of in vitro antimycotic and antimycobacterial activities of the compounds was carried out. The highest antituberculotic activity against M. tuberculosis in this series was shown by 3-anilino- 5-cyano-2-pyrazinecarboxamide (I), whose efficacy was the same as that of pyrazinecarboxamide.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1906
Author(s):  
Marissa Pérez-Alvarez ◽  
Gregorio Cadenas-Pliego ◽  
Odilia Pérez-Camacho ◽  
Víctor E. Comparán-Padilla ◽  
Christian J. Cabello-Alvarado ◽  
...  

Copper nanoparticles (CuNP) were obtained by a green synthesis method using cotton textile fibers and water as solvent, avoiding the use of toxic reducing agents. The new synthesis method is environmentally friendly, inexpensive, and can be implemented on a larger scale. This method showed the cellulose capacity as a reducing and stabilizing agent for synthetizing Cellulose–Copper nanoparticles (CCuNP). Nanocomposites based on CCuNP were characterized by XRD, TGA, FTIR and DSC. Functional groups present in the CCuNP were identified by FTIR analysis, and XRD patterns disclosed that nanoparticles correspond to pure metallic Cu°, and their sizes are at a range of 13–35 nm. Results demonstrated that CuNPs produced by the new method were homogeneously distributed on the entire surface of the textile fiber, obtaining CCuNP nanocomposites with different copper wt%. Thus, CuNPs obtained by this method are very stable to oxidation and can be stored for months. Characterization studies disclose that the cellulose crystallinity index (CI) is modified in relation to the reaction conditions, and its chemical structure is destroyed when nanocomposites with high copper contents are synthesized. The formation of CuO nanoparticles was confirmed as a by-product, through UV spectroscopy, in the absorbance range of 300–350 nm.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.


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