An Efficient Solvent-Free Synthesis of Bis(2-Tetrahydrobenzofuranyl)Alkanes Catalyzed by H2SO4•SiO2

2014 ◽  
Vol 1033-1034 ◽  
pp. 49-52
Author(s):  
Fan Zhang ◽  
Lu Lu Xiao ◽  
Lei Jin ◽  
Wen Bin Wang ◽  
Nian Yu Huang

A series of bis (2-tetrahydrobenzofuranyl) alkanes in good yield under solvent-free conditions from differently aromatic substituted aldehydes and 3-methyl-6,7-dihydrobenzofuran-4(5H)-one in the presence of H2SO4•SiO2 as catalyst at 90oC. Their structures were characterized by NMR, IR and ESI-MS. The proposed mechanism for the H2SO4•SiO2-catalyzed condensation reaction have been discussed in the work. This versatile approach has the advantages of broad functional group compatibility, short reaction times, simple operation and environmentally benign nature.

2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Saeed Khodabakhshi

Various coumarin derivatives have been efficiently synthesized via barium dichloride-catalyzed Pechmann condensation reaction of various phenols and β-keto esters under solvent-free conditions. This novel and inexpensive method has advantages such as short reaction times, excellent product yields, and avoidance of organic solvents in agreement with green chemistry principles.


2018 ◽  
Vol 42 (12) ◽  
pp. 604-607
Author(s):  
Loghman Firoozpour ◽  
Hoda Yahyavi ◽  
Ramona Ejtemaei ◽  
Setareh Moghimi ◽  
Alireza Foroumadi

A green and efficient method for preparing novel heterocyclic systems is established through the reaction of differently substituted benzaldehydes, barbituric acid and 4-amino-2H-chromene-2-one under solvent-free conditions. This method affords 6H-chromeno[3’,4’:5,6] pyrido[2,3-d]pyrimidine-trione derivatives in high yields and short reaction times.


2012 ◽  
Vol 9 (3) ◽  
pp. 1251-1256 ◽  
Author(s):  
Suresh Kumar ◽  
Jagdish K. Makrandi

An efficient method for the synthesis of 3-arylidenechroman-4-ones has been developed under solvent free conditions using grinding technique. Grinding of variously substituted chroman-4-ones with aromatic aldehydes in presence of anhydrous barium hydroxide at room temperature give 3-arylidenechroman-4-ones in high yield (75-92%). Products are obtained by just acidification of the reaction mixture in ice cold water. Reaction in solid state, with enhanced rate, high selectivity and manipulative simplicity are the attractive features of this environmentally benign protocol. The chroman-4-one derivatives required for the reaction have been obtained by polyphosphoric acid (PPA) catalysed cyclisation of phenoxypropanoic acids under microwave irradiations.


Author(s):  
CHIRAGKUMAR J GOHIL ◽  
MALLESHAPPA N NOOLVI

Objective: Amide is one of the most important functional group presents in the chemicals, pharmaceuticals, and foods. Conventionally, it has been synthesized from the carboxylic acid and amines. This conventional reaction is lengthy and involves hazardous chemicals and solvents. Hence, it poses waste management, solvent removal, and environmental issues to the industries. To overcome this limitation, we have reported the green chemistry-based method for the synthesis of amide from carboxylic acid and urea. Methods: In this reaction, we have used boric acid as a catalyst, it is a simple and readily available compound. It is simple, efficient, and solvent-free procedure which involves the trituration of the reactant mixture and subsequent, direct heating of the triturated mixture. Results: The rate of reaction is very high and can synthesize the amide quickly. Conclusion: Various amides were prepared in good yield by this technique.


2020 ◽  
Vol 17 (4) ◽  
pp. 304-312
Author(s):  
Leila Z. Fekri

Background: Imidazo[1,2-a]pyrimidinone, quinazolinone and amide derivatives have attracted a lot of interest because of their broad scope of biological and pharmacological activities. There are a lot of methods reported in the literature for their synthesis. Therefore, we became interested in developing a convenient synthetic method for the preparation of imidazoquinazolinone and amide derivatives. Objective: NiFe2O4@SiO2 @glucose amine were synthesized, characterized and have been used for the green, effective and mild multicomponent synthesis of quinazolinones, benzoimidazo[1,2-a]pyrimidinones and amides under solvent-free conditions in short reaction times and excellent yields. To expand of the scope of this avenue, multicomponent synthesis of mono and bis novel amides was tested for the first time. All of the products were characterized by mp, FT-IR, NMR and elemental analysis. Methods: Aldehyde (1mmol), 2-amino benzimidazole (1 mmol), dimedone (1mmol) or indane-1,3-dione (1 mmol) for the synthesis of quinazoline or imidazopyrimidinones and arene (1mmol), anhydride (1mmol), 2- aminobenzimidazole (1mmol) for the synthesis of amides in the nanocatalyst NiFe2O4@SiO2@glucose amine (0.15mol%: 0.05g) were stirred by a magnet for the required reaction time. After completion of the reaction, as indicated by TLC, the products were collected and recrystallized from ethanol if necessary. Results: We present a novel avenue for the synthesis of benzimidazo[1,2-a] pyrimidinones, quinazolinones and amides in the presence of NiFe2O4@SiO2@glucose amine under solvent-free conditions. Conclusion: In conclusion, we developed NiFe2O4@SiO2 @glucose amine-catalysed multicomponent synthesis of quinazolinones and imidazo[1,2-a]pyrimidinones using the reaction of benzaldehyde, dimedone or indane-dione and 2-aminobenzimidazole and multicomponent synthesis of amides using arenes, cyclic anhydrides and 2-aminobenzimidazole by a solvent-free technique. This method proves to be a robust and innovative approach for the synthesis of a biologically important structure. The operational simplicity, the excellent yields of products, ease of separation and recyclability of the magnetic catalyst, waste reduction and high selectivity are the main advantages of this method. Furthermore, this new avenue is cheap and environmentally benign.


2007 ◽  
Vol 85 (2) ◽  
pp. 81-84 ◽  
Author(s):  
Davood Habibi ◽  
Nosratollah Mahmoodi ◽  
Omid Marvi

Different phthalazino[2,3-b]phthalazine-5,7,12,14-tetraones were synthesized in a simple and environmentally benign method from the reaction of some phthalic anhydrides with semicarbazide or thiosemicarbazide using montmorillonite K-10 clay as solid heterogeneous acidic catalyst and microwaves under solvent-free conditions in good yields and short reaction times. The present method has many obvious advantages compared with those reported in the literature, including high efficiency, higher yield, operational simplicity, environmental benignity, and the possibility of recycling the solid clay. The solid clay catalyst used in the first cycle of the reactions was successfully recovered and reused in the second cycle, showing a gradual decrease in activity.Key words: montmorillonite K-10 clay, microwave, solvent-free condition, phthalazinetetraones, semicarbazide, thiosemicarbazide.


2021 ◽  
Vol 33 (6) ◽  
pp. 1299-1303
Author(s):  
Manpreet Kaur ◽  
Sumeet Kaur Bhatia ◽  
Baldev Singh

The environmentally benign catalyst and solvent-free synthesis of ketonitrones may not always be accomplished by simple condensation reactions. The occasional reports of green synthetic routes toward these compounds have been reported. The key features of this 1,3-dipolar cycloaddition reactions of N-[4-(-carboxycyclohexylmethyl)]maleimide with substituted isatin ketonitrone under microwave conditions resulted in the green synthesis of series of novel fluoro-substituted spiro[oxindole-isoxazolidine] derivatives in high yields, improved purity and short reaction times. All the synthesized compounds have been identified as potent in vitro antimicrobial agents. These results promoted the greener route to synthesize spiro[oxindole-isoxazolidine] derivatives with immense pharmacological importance in eco-friendly manner.


2016 ◽  
Vol 24 (1) ◽  
pp. 29-42
Author(s):  
Mojtaba Lashkari ◽  
Reza Heydari ◽  
Farzaneh Mohamadpour

Abstract The use of chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O) as an efficient, mild and economical catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives in the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehydes (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with good yields and short reaction times is reported. The most benefits of this synthetic method include the use of an efficient, eco-friendly, inexpensive and non-toxic catalyst, as well as the solvent-free conditions. All products were characterized by 1H NMR spectroscopy and melting point determination.


2011 ◽  
Vol 8 (s1) ◽  
pp. S462-S466 ◽  
Author(s):  
Seied Ali Pourmousavi ◽  
Maryam Hasani

H2SO4-Silica efficiently catalyzes the three-component condensation reaction of aldehydes, 1,3-dicarbonyl compounds and urea/thiourea under solvent free conditions to afford the corresponding dihydropyrimidinones and thio-derivatives in high yields. Compared to the classical Biginelli reaction conditions, this new method consistently has the advantage of giving good yields and requiring short reaction times.


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