نتایج جستجو برای: biginelli reaction

تعداد نتایج: 412492  

Montmorillonite modified is an efficient environmental friendly catalyst under one-pot-three-component synthesis of 3,4-dihydropyrimidine-2(1H) ones. The preparation was performed with an aldehyde, 1,3-dicarbonyl compounds, urea or thiourea under solvent-free conditions. In comparison with the other methods of Biginelli reaction, this new method has short reaction time inexpensive catalyst and ...

Mohammad Hosein Farjam Ramin Rezaei

An effective one-pot synthesis of dihydropyrimidinonoes in solvent free conditions using CuCl2 as an inexpensive and readily available reagent through Biginelli condensation reaction of aldehyde derivatives, 1,3-dicarbonyl compounds and urea is described. Excellent yields, short reaction times for formation of the products and simple work-up are attractive features of this green protocol.

Journal: :Organic & biomolecular chemistry 2011
Yangyun Wang Jipan Yu Zhiwei Miao Ruyu Chen

An enantioselective Biginelli reaction has been developed by using a bifunctional primary amine-thiourea-TfOH (BPAT·TfOH) as a chiral phase-transfer catalyst and t-BuNH(2)·TFA as an additive in saturated brine at room temperature. The corresponding dihydropyrimidines were obtained in moderate-to-good yields with up to 99% ee under mild conditions. A plausible transition state has been proposed ...

2012
Marcus Frings Isabelle Thomé Carsten Bolm

For the first time, chiral sulfoximine derivatives have been applied as asymmetric organocatalysts. In combination with a thiourea-type backbone the sulfonimidoyl moiety leads to organocatalysts showing good reactivity in the catalytic desymmetrization of a cyclic meso-anhydride and moderate enantioselectivity in the catalytic asymmetric Biginelli reaction. Straightforward synthetic routes prov...

ramin rezaei, sara ahmadi sedigheh abdollahi

A green methodology for the development of the synthesis of dihydropyrimidinones via a clean multi-component Biginelli reaction by using cyclohexane-1,4-diyl bis (hydrogen sulfate) (CDBH) as an effective catalyst in water and solvent-free conditions was reported. This sulfonated catalyst is an efficient and environmentally benign homogeneous catalysts which characterized by using different tech...

2008
C. Pothiraj A. Senthilkumara Velan J. Joseph N. Raman

A simple, efficient and cost effective method is described for the synthesis of Biginelli type heterocyclic compounds of dihydropyrimidinones analogous. They were prepared from a reaction mixture consisting of substituted benzaldehydes, thiourea and ethylacetoacetate using ammonium dihydrogenphosphate as catalyst. The procedure for the preparation of the compounds is environmentally benign and ...

Journal: :Bioorganic chemistry 2013
V Mallikarjuna Rao P Mahesh Kumar D Rambabu Ravikumar Kapavarapu S Shobha Rani Parimal Misra Manojit Pal

A series of novel alkynyl substituted 3,4-dihydropyrimidin-2(1H)-one (DHPM) derivatives were designed, synthesized and evaluated in vitro as potential inhibitors of chorismate mutase (CM). All these compounds were prepared via a multi-component reaction (MCR) involving sequential I2-mediated Biginelli reaction followed by Cu-free Sonogashira coupling. Some of them showed promising inhibitory ac...

Journal: :Dalton transactions 2008
Vadapalli Chandrasekhar Palani Sasikumar

The X-ray structural characterization of tritylphosphonic acid, Ph3CPO3H2 (), reveals that it possesses three different structural forms (a hexameric cage, a two-dimensional polymeric sheet and a dimer) depending upon the solvent used for crystallization. The reaction of cerium nitrate with under solvothermal conditions afforded a molecular dinuclear Ce(III) phosphonate, [Ce2{Ph3CPO2(OEt)}4(NO3...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید