Knoevenagel Condensation Of Aromatic Aldehydes Research Articles

Efficient Green Procedure for the Knoevenagel Condensation under Solvent‐Free Conditions

Knoevenagel condensation of aromatic aldehydes with active methylene compounds under solvent‐free conditions to synthesize arylidene compounds by grinding in the presence of TEBA at room temperature has been described. This method is simple, efficient, and environmentally friendly.

Amino-functionalized Ionic Liquid as an Efficient and Recyclable Catalyst for Knoevenagel Reactions in Water

The Knoevenagel condensation of aromatic aldehydes with malononitrile and ethyl cyanoacetate using amino-functionalized ionic liquid, 1-aminoethyl-3-methylimidazolium hexafluorophosphate as catalyst was successfully performed in aqueous media. The catalyst can be recycled and reused at least six times without apparently loss of activity. Open image in new window

Organic Reactions in Ionic Liquids: Ionic Liquids Ethylammonium Nitrate Promoted Knoevenagel Condensation of Aromatic Aldehydes with Active Methylene Compounds.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Amino group immobilized on polyacrylamide: An efficient heterogeneous catalyst for the Knoevenagel reaction in solvent-free and aqueous media

Modified polyacrylamide containing amino functionality was synthesized. It was an efficient catalyst for Knoevenagel condensation of aromatic aldehydes with ethyl cyanoacetate in water and solvent-free systems.

Organic Reactions in Ionic Liquids: Ionic Liquid Promoted Knoevenagel Condensation of Aromatic Aldehydes with (2‐Thio)barbituric Acid.

Organic Reactions in Ionic Liquids: Ionic Liquid Promoted Knoevenagel Condensation of Aromatic Aldehydes with (2‐Thio)barbituric Acid.

Organic Reactions in Ionic Liquids: Ionic Liquids Ethylammonium Nitrate Promoted Knoevenagel Condensation of Aromatic Aldehydes with Active Methylene Compounds

The Knoevenagel condensation of aromatic aldehydes with active methylene compounds proceeded efficiently in a reusable ionic liquid, ethylammonium nitrate, at room temperature in the absence of any catalyst with high yields.

A Practical Knoevenagel Condensation Catalyzed by PEG400 and Anhydrous K2CO3 Without Solvent.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Organic Reactions in Ionic Liquids: Ionic Liquid Promoted Knoevenagel Condensation of Aromatic Aldehydes with (2‐Thio)Barbituric Acid

The Knoevenagel condensation of aromatic aldehydes with (2‐thio)barbituric acid proceeded efficiently in reusable ionic liquids, EAN, BmimBF4, and BmimPF6 at room temperature in the absence of any catalyst with high yields.

A Practical Knoevenagel Condensation Catalyzed by PEG400 and Anhydrous K2CO3 Without Solvent

Knoevenagel condensation of aromatic aldehydes with active methylene compounds under solvent‐free conditions to synthesize arylidene compounds in good to excellent yields using powdered anhydrous K2CO3 and PEG400 as catalysts has been described.

A Convenient Synthesis of 5‐Benzylidenethiazolidine‐2,4‐diones under Microwave Irradiation Without Solvent.

A series of 5-benzylidenethiazolidine-2,4-diones was synthesised by the Knoevenagel condensation of aromatic aldehydes with thiazolidine-2,4-dione in the presence of catalytic amounts of piperidine and acetic acid under microwave irradiation without solvent in good yields.

Microwave Assisted Knoevenagel Condensation Using Sodium Fluoride and Lithium Chloride as Catalysts under Solvent‐Free Conditions.

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A Convenient Synthesis of 5-Benzylidenethiazolidine-2, 4-Diones under Microwave Irradiation without Solvent

A series of 5-benzylidenethiazolidine-2,4-diones was synthesised by the Knoevenagel condensation of aromatic aldehydes with thiazolidine-2,4-dione in the presence of catalytic amounts of piperidine and acetic acid under microwave irradiation without solvent in good yields.

Microwave Assisted Knoevenagel Condensation Using Sodium Fluoride and Lithium Chloride as Catalysts Under Solvent-Free Conditions

Microwave assisted Knoevenagel condensation of aromatic aldehydes 1 with active methylene compounds 2 under solvent free conditions to prepare arylidene compounds 3 in excellent yields using cheap and readily available NaF and LiCI as catalysts has been described.

Knoevenagel Condensation of Aldehydes with Cyclic Active Methylene Compounds in Water.

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Knoevenagel Condensation in the Heterogeneous Phase using KF-Montmorillonite as a New Catalyst

The Knoevenagel condensation of aromatic aldehydes was carried out in DMF as solvent on KF-Montmorillonite catalyst, using malononitrile and ethyl cyanoacetate as the acidic methylene reagents. Only the e isomers of the products were obtained and confirmed by X-ray analysis.

KNOEVENAGEL CONDENSATION OF ALDEHYDES WITH CYCLIC ACTIVE METHYLENE COMPOUNDS IN WATER

ABSTRACT A new route of Knoevenagel condensation of aromatic aldehydes with Meldrum's acid, barbituric acid and dimedone in the presence of cetyltrimethyl ammonium bromide at room temperature in water is described.

ChemInform Abstract: Knoevenagel Condensation of Aromatic Aldehydes with Malononitrile or Ethyl Cyanoacetate in the Presence of CTMAB in Water.

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Synthesis and characterization of dyes exemplified by 2-arylidene-1-dicyanomethyleneindane

The synthesis of methine dyes formed by Knoevenagel condensation of aromatic aldehydes with 1-dicyanomethylene indane 2 afforded a novel series of dyes absorbing in the region 490–593 nm. Substituents on the aromatic aldehyde moiety have a significant effect on the visible absorption maxima of the dyes; increasing the solvent polarity also had a pronounced effect on the absorption maxima.

The ultrasound promoted Knoevenagel condensation of aromatic aldehydes

Application of ultrasound has been found to greatly assist the Knoevenagel aldol condensation reaction of activated methylenes with aromatic aldehydes under mild conditions. The outcome of the ultrasound-promoted reaction depends upon the electronic nature of the armoatic aldehyde, the solvent employed and the addition of acids, bases or ammonium salts.

The knoevenagel condensation of ethyl acylpyruvates

AbstractExtensive studies of the Knoevenagel condensation of aromatic aldehydes and active methyl‐lene compounds have been reported (2). In 1894, Knoevenagel reported (3) the reaction of benz‐aldehyde with ethyl benzoylpyruvate in the presence of piperidine to give ehtyl benzyl‐(bis‐benzoyl)pyruvate, m.p. 162°, but no yield of the product was reported. This paper deals with the interesting results of the reactions of ethyl acetylpyruvate (2) (4) and ethyl benzoylpyruvate (3) (5) with some aromatic aldehydes (1a‐f).