نتایج جستجو برای: green solvent

تعداد نتایج: 193244  

Journal: :Technology audit and production reserves 2017

Foad Buazar, Zohreh Dehghanizadeh

In this study, multi component Hantzsch reaction was carried out between various  Aromatic Aldehyde with Dimedone,Ethyl acetateand ammonium acetate to produce polyhydroquinolinederivatives under solvent-free conditions at 110oC by a (Zinc oxide  nanocatalyst) as effective Lewis acid. The remarkable advantages offered by this method compared with other methods are a green catalyst, simple work-u...

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.

Azam Mansournezhad Jalal Albadi,

CuO-CeO2 nanocomposite is reported as a green and highly efficient recyclable catalyst for the multicomponent  synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones under solvent-free conditions. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, FESEM and EDS analysis.

Javad Safaei-Ghomi, Mohammad Ali Ghasemzadeh Safura Zahedi

An efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the c...

Journal: :African journal of traditional, complementary, and alternative medicines : AJTCAM 2014
Faiza M Hammouda Mahmoud A Saleh Nahla S Abdel-Azim Khaled A Shams Shams I Ismail Abdelaaty A Shahat Ibrahim A Saleh

BACKGROUND Hydrodistillation (HD) and steam-distillation, or solvent extraction methods of essential oils have some disadvantages like thermal decomposition of extracts, its contamination with solvent or solvent residues and the pollution of residual vegetal material with solvent which can be also an environmental problem. Thus, new green techniques, such as supercritical fluid extraction and m...

Hassan Kefayati Seyyedeh Cobra Azimi,

A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this pro...

Journal: :iranian journal of catalysis 2015
leila moradi mina zare

a simple, mild and high efficient procedure for one pot three component synthesis of 2-amino 4-h chromene derivatives was studied. the reaction was performed in water using aryl aldehydes, malononitrile and resorcinol, phloroglucinol or naphthole in the presence of n-methyl d-glucamine (meglumine) as a green high efficient catalyst. the reaction was studied in thermal, microwave (mw) and ultras...

2014
Mohammad Asif

In alkaline medium the benzil reacts with urea or thiourea in presence of base like 30% w/v NaOH, using ethanol as solvent to give the cyclic hydantoin compounds, or phenytoin (5,5’dipenylimidazolidine-2,4-dione) and thiohydantoin (5,5-diphenyl-2-thioimidazolidine-4-one) respectively. The first step in the reaction involve the attack by urea or thiourea on the carbonyl group of the benzil to gi...

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