Samarium Chloride Catalysed Biginelli Reaction: One-Pot synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones

2002 ◽  
Vol 2002 (9) ◽  
pp. 436-438 ◽  
Author(s):  
Xuesen Fan ◽  
Xinying Zhang ◽  
Yongmin Zhang

An efficient synthesis of 3,4-dihydropyrimidin-2(1 H)-one derivatives using samarium chloride as a catalyst from aldehyde, β-keto ester and urea or thiourea in ethanol is described; compared to the classical Biginelli method, this new method has the advantages of good yields and milder reaction conditions.

2005 ◽  
Vol 2 (4) ◽  
pp. 228-230 ◽  
Author(s):  
Jin Tong-Shou ◽  
Zhao Ying ◽  
Liu Li-Bin ◽  
Li Tong-Shuang

An efficient synthesis of 3,4-dihydropyrimidin-2-ones (DHPMs) from the aldehydes, β-ketoesters and urea in ethanol using chlorosulfonic acid as the catalyst is described. Compared with the classical Biginelli reaction conditions, this method has the advantage of excellent yields and short reaction time.


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.


2017 ◽  
Vol 15 (33) ◽  
pp. 6997-7007 ◽  
Author(s):  
Anirban Kayet ◽  
Vinod K. Singh

Pd(ii)–Ag(i) catalysed, highly efficient synthesis of diindolylmethanes under mild reaction conditions, with six new bonds being formed in a one-pot fashion, and the products being transformed into synthetically useful compounds.


2002 ◽  
Vol 2002 (1) ◽  
pp. 37-39 ◽  
Author(s):  
Tongshou Jin ◽  
Suling Zhang ◽  
Suyun Zhang ◽  
Junjie Guo ◽  
Tongshuang Li

A general and practical route for the synthesis of dihydropyrimidines by the one-pot cyclocondensation of aldehydes, β-ketoesters and urea is described using NH2SO3H as catalyst. Yields and selectivities are significantly better than under classical Biginelli reaction conditions.


2020 ◽  
Vol 02 (04) ◽  
pp. 306-312
Author(s):  
Jan H. Griwatz ◽  
Hermann A. Wegner

The preparation of cycloparaphenylenes ([n]CPPs) with their bent π-system poses a long-standing challenge in organic synthesis. In the current multi-step approaches to access CPPs, pre-angulated precursors were combined using transition metal-catalysed or mediated coupling reactions. Therefore, there is a long way to the realisation of the idea of an ‘ideal synthesis’. An easy and efficient synthesis of different [n]CPPs would represent a breakthrough, also pushing their incorporation into organic materials. By combining multiple steps in a one-pot approach, the overall time and workload can be drastically shortened. Herein, we present the application of this concept for the preparation of [6] and [9]CPP as a simple and fast alternative to current methods. By tuning the reaction conditions the selective synthesis of both [6] and [9]CPP was demonstrated.


2003 ◽  
Vol 2003 (9) ◽  
pp. 544-545 ◽  
Author(s):  
Shujang Tu ◽  
Fang Fang ◽  
Chunbao Miao ◽  
Hong Jiang ◽  
Daqing Shi ◽  
...  

A simple effective synthesis of 3,4-dihydropyrimidin-2(1 H)-one derivatives from aromatic aldehydes, 1,3-dicarbonyl compounds and urea in glacical acetic acid using cadmium sulfate as catalyst is described and compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yields (83–94%) and short reaction time (2-4 h).


2020 ◽  
Vol 17 ◽  
Author(s):  
Visarapu Malathi ◽  
Pedavenkatagari Narayana Reddy ◽  
Pannala Padmaja

Abstract:: An efficient method has been developed for the synthesis of new pyrano[3,2-c] and pyrano[3,2-a]carbazole de-rivatives via a three component reaction of 4-hydroxycarbazole or 2-hydroxycarbazole, isocyanides, and dialkylacetylenedi-carboxylates. Noteworthy features of this protocol include mild reaction conditions, catalyst-free, high atom-economy and high yields.


2020 ◽  
Vol 56 (55) ◽  
pp. 7665-7668 ◽  
Author(s):  
Lu Liu ◽  
Lei Li ◽  
Shukuan Mao ◽  
Xin Wang ◽  
Ming-Dong Zhou ◽  
...  

Various o-alkenyl aromatic isocyanides were prepared from readily available reactants for their double annulation with diazo compounds for a one-pot synthesis of pyrazolo[1,5-c]quinazolines under mild reaction conditions.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1466
Author(s):  
Ye Eun Kim ◽  
Hyunsung Cho ◽  
Yoo Jin Lim ◽  
Chorong Kim ◽  
Sang Hyup Lee

Studies on a one-pot synthesis of novel multisubstituted 1-alkoxyindoles 1 and their mechanistic investigations are presented. The synthesis of 1 was successfully achieved through consecutive four step reactions from substrates 2. The substrates 2, prepared through a two-step synthetic sequence, underwent three consecutive reactions of nitro reduction, intramolecular condensation, and nucleophilic 1,5-addition to provide the intermediates, 1-hydroxyindoles 8, which then were alkylated in situ with alkyl halide to afford the novel target products 1. We optimized the reaction conditions for 1 focusing on the alkylation step, along with the consideration of formation of intermediates 8. The optimized condition was SnCl2·2H2O (3.3 eq) and alcohols (R1OH, 2.0 eq) for 1–2 h at 40 °C and then, base (10 eq) and alkyl halides (R2Y, 2.0 eq) for 1–4 h at 25–50 °C. Notably, all four step reactions were performed in one-pot to give 1 in good to modest yields. Furthermore, the mechanistic aspects were also discussed regarding the reaction pathways and the formation of side products. The significance lies in development of efficient one-pot reactions and in generation of new 1-alkoxyindoles.


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