نتایج جستجو برای: 4 dihydropyrimidin 2 1h one

تعداد نتایج: 4524330  

Journal: :iranian chemical communication 2016
saeid azimi marziyeh hariri

in this work, the ionic liquid triethylamine-bonded sulfonic acid {[et3n–so3h]cl}, n,n-diethyl-n-sulfoethanammonium chloride was used as a green acidic homogeneous catalyst to synthesis of 3,4-dihydropyrimidin-2(1h)-ones and 3,4-dihydropyrimidin-2(1h)-thiones as two categories of heterocycles, from aldehyde, dicarbonyl compound and urea or thiourea throughout the one-pot three components cycloc...

Heshmatollah Alinezhad, Neda Ghobadi

An efficient and convenient procedure for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and thiones by condensation of 1,3-dicarbonyl compounds, Aromatic and aliphatic aldehydes, and urea or thiourea in the presence of catalytic amount of Brønsted acidic ionic liquid 3-methyl-1-sulfonic acid imidazolium chloride {[Msim]Cl} under thermal solvent-free conditions reacted easily to afford the co...

Journal: :Acta Crystallographica Section E Structure Reports Online 2010

Journal: :Acta Crystallographica Section E Structure Reports Online 2009

Hojjatollah Salehi

Simple and improved conditions have been found to carry out the Biginelli reaction for the synthesis of 3, 4-dihydropyrimidin-2(1H) - one derivatives. This synthesis was performed in the presence of 12-molybdophosphoric acid (H3PMo12O40) as catalyst. These reactions were performed under solvent free conditions with microwave irradiation as the energy source. Compared with the classical Biginell...

Oxalic acid dihydrate as a green, mild and efficient catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives from the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehyde (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with excellent yields and short reaction time is st...

Journal: :Organic & biomolecular chemistry 2014
Olga P Pereshivko Vsevolod A Peshkov Anatoly A Peshkov Jeroen Jacobs Luc Van Meervelt Erik V Van der Eycken

Cationic gold-catalyzed cycloisomerizations of propargylureas, derived in situ from secondary propargylamines and aryl or alkyl isocyanates, have been studied. The reaction outcome was found to be different from what was previously observed for the tosyl isocyanate-derived ureas in terms of both regio- and chemoselectivity. As a result, the current protocol offers efficient access to the 3,4-di...

Ali Oudi Maryam Fatahpour Nourallah Hazeri,

In this research, one-pot three-component synthesis of 3,4-dihydropyrimidin-2-(1H)-ones havebeen developed using Biginelli reaction from the interaction between ethyl/methyl acetoacetate,aromatic aldehydes, and urea/thiourea in the presence of 4-sulfobenzoic acid as a new, effective,inexpensive, and available bronsted acid. Avoidance of toxic and dangerous solvents, easy isola...

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