scholarly journals A Green, Expeditious, One-Pot Synthesis of 3, 4-Dihydropyrimidin-2(1H)-ones Using a Mixture of Phosphorus Pentoxide-Methanesulfonic Acid at Ambient Temperature

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Amulrao Borse ◽  
Mahesh Patil ◽  
Nilesh Patil ◽  
Rohan Shinde

An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton’s reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure.

2015 ◽  
Vol 69 (11) ◽  
Author(s):  
Masoud Nasr-Esfahani ◽  
Morteza Montazerozohori ◽  
Tooba Abdizadeh

AbstractNanorod vanadatesulfuric acid (VSA NRs), as a recyclable and eco-benign catalyst, was used for one-pot synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles using aldehydes, benzil, benzoin or 9,10-phenanthrenequinone and ammonium acetate or aniline under solvent-free conditions providing high to excellent yields. VSA is easily prepared by a simple reaction of chlorosulfonic acid and sodium metavanadate in high purity. As compared with the conventional procedures, the present protocol offers several advantages such as simplicity of procedure, short reaction time, high yields, easy workup, recoverability and reusability of the catalyst and simple purification of the products.


2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Abolghasem Davoodnia ◽  
Sadegh Allameh ◽  
Samineh Fazli ◽  
Niloofar Tavakoli-Hoseini

AbstractA convenient method for the synthesis of tetrahydrobenzo[b]pyrans by a one-pot three-component cyclocondensation of dimedone, aryl aldehydes, and malononitrile in water using silica gel-supported polyphosphoric acid (PPA-SiO2) as an efficient and reusable catalyst is described. The present methodology offers several advantages, such as a simple procedure with ease of handling, short reaction time, high yields, and the absence of any volatile and hazardous organic solvents.


2020 ◽  
Vol 17 (7) ◽  
pp. 518-524
Author(s):  
Shailesh Singh ◽  
Jyoti Tiwari ◽  
Deepali Jaiswal ◽  
Amit Kumar Sharma ◽  
Jaya Singh ◽  
...  

Background: A novel one-pot N-heterocyclic carbene (NHC)-catalysed acylation of 2- bromoacetonitrile with aromatic aldehydes is reported. The protocol involves carbonyl umpolung reactivity of aldehydes in which the carbonyl carbon attacks nucleophilically (as d1 nucleophile) on the electrophilic terminal of 2-bromoacetonitrile to afford 3-aryl-3-oxopropanenitrile. The salient features of this procedure are short reaction time, operational simplicity, ambient temperature, no by-product formation and high yields. Materials and Methods: A flame-dried round bottom flask was charged with Imidazolium salts (3a) (0.20 mmol). Aldehyde 1a (1.0 mmol), 2-bromoacetonitrile 2 (1.0 mmol), and THF / t-BuOH 5 mL; 10:1) were added at positive nitrogen pressure followed by the addition of DBU (0.15 mmol) through stirring. The resulting yellow- orange solution was stirred at room temperature for 5-6 h. After completion of the reaction (TLC monitored), the reaction mixture was concentrated under reduced pressure. The product was purified using hexane / EtOAc (10:1) as an eluent to provide analytically pure compound 4a. Physical data of representative compounds and the NMR spectroscopic data are in agreement with the literature value. Results and Discussion: The salient features of this procedure are short reaction time, operational simplicity, ambient temperature, no by-product formation and high yields. Conclusion: To sum up, we have developed a convenient, efficient and one-pot route for 3-oxo-3- phenylpropanenitrile synthesis from NHC promoted direct nucleophilic acylation of aromatic aldehydes using 2- bromoacetonitrile. This method provided a wide range of products and good yields. To best of our knowledge, this is the new report for the synthesis of 3-oxo-3-phenylpropanenitrile through NHC promoted nucleophilic acylation of aromatic aldehyde.


2008 ◽  
Vol 61 (11) ◽  
pp. 860 ◽  
Author(s):  
Weike Su ◽  
Jia Li ◽  
Jianjun Li

A straightforward and green synthesis of polyhydroquinoline derivatives was reported via a four-component coupling reaction of aldehydes, dimedone, active methylene compounds, and ammonium bicarbonate in the presence of 5-pyrrolidin-2-yltetrazole under solvent-free conditions. The method offers several advantages including high yields, an environmental friendly procedure, a short reaction time, and easy isolation of products.


2020 ◽  
Vol 17 (6) ◽  
pp. 438-442
Author(s):  
Xiaofang Ma ◽  
Shunxi Li ◽  
Samrat Devaramani ◽  
Guohu Zhao ◽  
Daqian Xu

The elimination of volatile organic solvents in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator under solvent-free conditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally simple, excellent product yields, high regioselectivity and organic solvent-free.


2017 ◽  
Vol 41 (2) ◽  
pp. 85-87 ◽  
Author(s):  
Ghodsyeh Keykha ◽  
Mohammad R. Hosseini-Tabatabaei ◽  
Alireza Hassanabadi

Good yields of six 1H-chromeno[2,3-d]pyrimidine-5-carboxamides were obtained via the two-stage, one-pot reaction of an alkyl isocyanide with the initially formed condensation product of 1,3-dimethyl barbituric acid and a salicylaldehyde under solvent-free conditions at ambient temperature. This procedure has a number of advantages, such as short reaction time and easy work-up. Also, the present method does not involve any hazardous organic solvent.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maryam Kamalzare ◽  
Mohammad Reza Ahghari ◽  
Mohammad Bayat ◽  
Ali Maleki

AbstractRecently magnetic nanocatalyst has attracted considerable attention because of its unique properties, including high performance, easy separation from the reaction mixture, and recyclability. In this study, a novel magnetic bionanocomposite was synthesized with chitosan and tannic acid as a natural material. The synthesized bionanocatalyst was characterized by essential analysis. Fe3O4@chitosan-tannic acid as a heterogeneous nanocatalyst was successfully applied to synthesize pyranopyrazole and its derivatives by a one-pot four-component reaction of malononitrile, ethyl acetoacetate, hydrazine hydrate, and various aromatic aldehyde. At the end of the reaction, the nanocatalyst was separated from the reaction mixture and was reused several times with no significant decrease in its catalytic performance. Simple purification of products, the ability for recovering and reusing the nanocatalyst, eco-friendliness, high yields of pure products, mild reaction conditions, short reaction time, non-toxicity, economically affordable are some of the advantages of using the fabricated nanocatalyst in the synthesis of pyranopyrazole.


2012 ◽  
Vol 9 (4) ◽  
pp. 2037-2043 ◽  
Author(s):  
Abolghasem Davoodnia ◽  
Bahareh Razavi ◽  
Niloofar Tavakoli-Hoseini

Silica gel-supported polyphosphoric acid (PPA-SiO2) was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the synthesis of 2,4,6-triarylpyridines through one-pot three-component reaction of acetophenone, aryl aldehydes, and ammonium acetate under solvent-free conditions. This method has several advantages, such as simple procedure with an easy work-up, short reaction times, and high yields. Furthermore, the catalyst could be recycled after a simple work-up, and used at least three times without substantial reduction in its catalytic activity.


2020 ◽  
Vol 9 (1) ◽  
pp. 72-79
Author(s):  
Jhansi R. Sunkara ◽  
Sathish M. Botsa

Background: Metal oxide or metal oxide composite nanoparticles are attaining tremendous importance due to their catalytic activities for various organic transformations. Objective: To report the one-pot synthesis of xanthene derivatives prepared by ZnS-Fe2O3-Ag composite under solvent-free conditions. Method: To prepare nanocomposite by a facile and simple hydrothermal approach. Results: The prepared composite is smaller (17.56 nm) in size and can be easily separable, recycled and reused six times without any significant loss of catalytic activity with excellent yields. In short reaction time, great catalytic activity was perceived with no co-catalyst and any other activator. Conclusion: In conclusion, ZnS-Fe2O3-Ag composite provides a simple, economical, efficient and greener method for the synthesis of one-pot multicomponent reaction of aldehyde with 1,3-diketones under solvent free conditions for the synthesis of 1,8-dioxooctahydro xanthenes. In short reaction time, great catalytic activity was perceived with no co-catalyst and any other activator.


2019 ◽  
Vol 25 (1) ◽  
pp. 157-161 ◽  
Author(s):  
Shin-taro Katayama ◽  
Hiroshi Nishino

AbstractSpiro[cyclohexane-1,3’-indoline]-2,2’-diones were easily prepared in good to high yields by the oxidation of N-aryl-N-methyl-2-oxocyclohexane-1-carboxamides in one pot with a short reaction time. The spiroindolinediones could be important for the total synthesis of natural products.


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