The Synthesis of α-Hydroxyphosphonates Mediated by Microwave Irradiation under Solvent-Free Conditions

2002 ◽  
Vol 2002 (6) ◽  
pp. 291-292 ◽  
Author(s):  
Babak Kaboudin ◽  
Rahman Nazari

Microwave-assisted hydrophosphonylation of aldehydes under solvent-free conditions was found to be an efficient method for the preparation of α-hydroxyphosphonates; the method was reliable, efficient and high yielding.

2005 ◽  
Vol 2005 (1) ◽  
pp. 27-28 ◽  
Author(s):  
Jaime Charris ◽  
Arthur Barazarte ◽  
José Domínguez ◽  
Neira Gamboa

A rapid method for the preparation of N-aryl-2-methylthio-4-oxo-1,4-dihydro quinoline-3-carbonitriles (2a–e) and N-aryl-3-methylthio-4H-1,4-benzothiazine-2-carbonitrile 1,1-dioxides (2f–o) is reported. The cyclization is accelerated by microwave irradiation under solvent free conditions in the presence of K2CO3.


RSC Advances ◽  
2014 ◽  
Vol 4 (46) ◽  
pp. 24001-24006 ◽  
Author(s):  
Kommuri Shekarrao ◽  
Partha Pratim Kaishap ◽  
Venkateshwarlu Saddanapu ◽  
Anthony Addlagatta ◽  
Sanjib Gogoi ◽  
...  

An efficient method was developed for the synthesis of pyrazole fused heterocycles via the palladium-catalyzed solvent free reaction of β-halovinyl/aryl aldehydes and 3-aminopyrazoles/5-aminopyrazoles under microwave irradiation in good yields.


2020 ◽  
Vol 55 (2) ◽  
pp. 159-164
Author(s):  
WT Purba ◽  
PS Roy ◽  
S Jannat ◽  
SA Begum ◽  
MM Rahman

Rapid and efficient method for the synthesis of substituted olefins such as 2-(4-chlorophenylmethylene) malononitrile, 2-(4-hydroxyphenylmethylene) malononitrile and 2-cyano-3-(4-hydroxyphenyl) acrylamide etc under the influence of microwave irradiation are described. Urea has been utilized as an efficient catalyst for the Knoevenagel condensation of aldehydes with acidic active methylene compounds such as malononitrile, ethylcyanoacetate and cyanoacetamide to afford substituted olefins under the influence of microwave irradiation. The reaction proceeds smoothly under mild and solvent free conditions and the products are obtained in good yield. The method is applicable for a wide range of aldehydes including aromatic and heterocyclic substrates. Bangladesh J. Sci. Ind. Res.55(2), 159-164, 2020


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.


2005 ◽  
Vol 2005 (1) ◽  
pp. 71-72 ◽  
Author(s):  
Xi-Cun Wang ◽  
Zheng-Jun Quan ◽  
Zheng Li

Thirty-two 1-aroyl/aryloxyacetyl-4-(2-furoyl)thiosemicarbazides and corresponding semicarbazides were synthesised in excellent yields under microwave irradiation and solvent-free conditions without using any catalyst.


RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 78225-78233 ◽  
Author(s):  
Luísa M. D. R. S. Martins ◽  
Susanta Hazra ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro

The sulfonated Schiff base dimethyltin(iv) coordination polymer is an efficient heterogeneous catalyst for the peroxidative Baeyer–Villiger oxidation of ketones, under ultrasound or microwave irradiation and solvent- and additive-free conditions.


2005 ◽  
Vol 83 (3) ◽  
pp. 260-265 ◽  
Author(s):  
Surinderjit Singh ◽  
M PS Ishar ◽  
Gajendra Singh ◽  
Rajinder Singh

Contrary to literature reports, the o-allyloxy- and crotyloxy-acetophenone-oximes (2a, 2b) are transformed to nitrones, which undergo regio- and stereoselective intramolecular 1,3-dipolar cycloadditions, both on microwave heating under solvent free conditions and refluxing in toluene, to afford novel cycloadducts (5a, 5b); the oxazepine-N-oxide (3a) reported to be formed in 98% yield was obtained only as a minor product (~10%). However, o-cinnamyloxy-acetophenone-oxime (2c) under similar conditions undergoes intramolecular N-alkylation to afford nitrone (3c). The reactions carried out under microwave irradiation are cleaner, require shorter reaction times, and have higher yields. Corresponding intramolecular 1,3-dipolar cycloadditions of N-methylnitrones (B), generated in situ from o-alkenylmethoxy-acetophenones (1a–1c) and N-methylhydroxylamine under solvent-free microwave irradiation conditions, are completely regio- and stereoselective, require much shorter reaction times, and afford adducts (4a–4c) in higher yields, as compared with their thermal counterparts.Key words: cycloadditions, nitrones, oximes, o-alkenylmethoxy-acetophenones, microwave, isoxazolidines.


2015 ◽  
Vol 80 (4) ◽  
pp. 459-464
Author(s):  
Hoorieh Djahaniani ◽  
Laila Aghadadashi-Abhari ◽  
Bita Mohtat

Microwave-assisted three-component reaction has been established for the synthesis of aryl alkyl ethers. The reaction was carried out under solvent free conditions in the presence of N-methylimidazole and dialkylacetylenedicarboxylate to furnish a novel approach to O-alkylation of phenol derivatives in high yield


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