One-Pot Synthesis of N-Substituted 4-Aryl-1,4-dihydropyridines Under Solvent-Free Conditions and Microwave Irradiation

Summary.  The three-component condensation of benzaldehyde derivatives, alkyl propiolates, and primary amines catalyzed by silica gel, zeolite HY, montmorillonite K-10, and acidic alumina under microwave irradiation gave N-substituted 4-aryl-1,4-dihydropyridines in short reaction times and high yields. The best results were obtained with silica gel. Received March 26, 2001. Accepted (revised) June 18, 2001     

One-Pot Synthesis of N-Substituted 4-Aryl-1,4-dihydropyridines Under Solvent-Free Conditions and Microwave Irradiation

 The three-component condensation of benzaldehyde derivatives, alkyl propiolates, and primary amines catalyzed by silica gel, zeolite HY, montmorillonite K-10, and acidic alumina under microwave irradiation gave N-substituted 4-aryl-1,4-dihydropyridines in short reaction times and high yields. The best results were obtained with silica gel.     

Facile One-Pot,Multicomponent Synthesis of Pyridines Under Microwave Irradiation

A series of 2-amino-6-(2-oxo-2H-chromen-3-yl)-4-pyridine-3-carbo-nitriles were synthesized by the one-pot, multicomponent reaction of 3-acetyl-coumarin, aromatic aldehydes, malononitrile, and ammonium acetate in acetic acid under microwave irradiation. The reactions were completed in 10–13 min with 61–86% yields, were environmental benign, and had easy workup. Their structures were confirmed by ¹H NMR, IR, and MS spectra and elemental analysis.     

Synthesis of Sodium Diselenides and its Reaction with Benzoyl Chloride Under Phase Transfer Catalysis and Microwave Irradiation Conditions

A simple, fast and efficient procedure for the synthesis of dibenzoyl diselenides involves the reaction of selenium with sodium hydroxide under phase transfer catalysis and microwave irradiation conditions to give sodium diselenides, which reacts with benzoyl chloride at 0-3 °C and conventional conditions to afford the dibenzoyl diselenides. The effect of microwave irradiation power, reaction time, solvent and operational method on the reaction is investigated.     

Efficient One-Pot Synthesis of 3-Amino-7-azaindoles Under Microwave Irradiation

An efficient one-pot synthesis of 3-amino-7-azaindoles was developed, starting from ethyl (3-cyanopyridin-2-yl)carbamate and α -bromoketones by microwave-assisted Thorpe–Ziegler cyclization in the presence of a base. This method features excellent yields, short reaction time (10min), and high functional group compatibility.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

简便合成二酰基二硒醚

芳基硒代酰胺与酰氯以1∶1的摩尔比在氯仿溶液中作用, 可以较高的产率得到二酰基二硒醚, 而芳基硒代酰胺与酰氯以1∶2的摩尔比反应时则生成二酰基硒醚. 提出了反应可能的机理.     

微波辐射下苯并噁唑基吡啶的合成

在微波辐射条件下,利用邻氨基酚和吡啶羧酸在多聚磷酸中的缩合反应,合成了2种苯并唑基取代吡啶 最佳反应条件为:450W辐射4min 相比于常规反应,反应时间大为缩短且产率令人满意     

A Rapid and Convenient Synthesis of Derivatives of Imidazoles under Microwave Irradiation

An efficient and a quick microwave‐assisted synthesis of benzimidazoles and trisubstituted imidazoles was developed. Three benzimidazoles were obtained as a result of the condensation of 1,2‐phenylenediamine with carboxylic acids and acetoacetic ester without catalyst. A series of trisubstituted imidazoles were synthesized by condensation of benzil, aromatic aldehyde and ammonium acetate in the presence of glacial acetic acid.     

An Efficient One-Pot Synthesis of Nitriles from Carboxylic Acids Without Solvent Under Microwave Irradiation

Nitriles were prepared from alkyl and aryl carboxylic acids in dry media conditions, under microwave irradiation. Heating of the carboxylic acid, urea and amidosulfonic acid adsorbed on alumina support in a microwave oven affords nitriles in 20–93% yields.     

Synthesis of Ferrocenyl Schiff Bases Under Solvent-Free Conditions Using Microwave Irradiation

Ferrocenyl imines 3a–f were synthesized using solvent-free methods by mixing ferrocene carbaldehyde 1 with amines 2a–f under microwave irradiation. The imines were obtained in good yield in short reaction times.     

One-Pot Synthesis of Salicylanilides by Direct Amide Bond Formation from Salicyclic Acid Under Microwave Irradiation

A highly efficient protocol for the preparation of aromatic amides is described by the direct reactions between salicyclic acid and aromatic amines in the presence of phosphorous trichloride under microwave irradiation. The method has several advantages over the conventional methods, including operational simplicity, good yield, and reduced reaction time.

Efficient One-Pot Synthesis of Tetrahydrobenzo[c]xanthene-1,11-dione Derivatives Under Microwave Irradiation

An efficient one-pot condensation of 4-hydroxylcoumarin, aromatic aldehydes, and 5,5-dimethylcyclohexane-1,3-dione has been achieved with molecular iodine as a catalyst via conventional heating and microwave irradiation techniques, and thus a variety of new tetrahydrobenzo[c]xanthene-1,11-dione derivatives were prepared in good yields.     

Synthesis of Thiosemicarbazones Under Microwave Irradiation

Thiosemicarbazones (3) are effectively synthesized in a few minutes by the condensation reaction of aldehydes with thiosemicarbazide under microwave irradiation.     

Three-Component,One-Pot Synthesis of 2,4,5-Trisubstituted Imidazoles Catalyzed by TiCl4-SiO2 Under Conventional Heating Conditions or Microwave Irradiation

In this study, silica-supported titanium tetrachloride was prepared and used as a novel catalyst for rapid and efficient synthesis of 2,4,5-trisubstituted imidazoles by a three-component, one-pot condensation of 1,2-diketones and aryl aldehydes in excellent yield under solvent-free conditions using conventional heating or microwave irradiation.

A Convenient One-Pot Synthesis of Phosphino-Dipeptide Analogs

A general "one-pot" synthetic method is described for the preparation of phosphinodipeptides of type 1 , in 60-80% overall yield, allowing the variation of the substituents in f and/or g position to the phosphorus atom and also in f position to the nitrogen atom.     

Synthesis of Guanylhydrazones Under Microwave Irradiation

Abstract

The reaction of aromatic aldehydes and ketones with aminoguanidine hydrochloride under microwave irradiation (MWI) afforded guanylhydrazones in shorter reaction times and improved yield as compared to the conventional methodology.     

A Convenient One-Pot Synthesis of Di-t-butylphosphinic Chloride

A convenient one-pot synthesis of (t-Bu)₂P(O)Cl (1) from m-chloroperbenzoic acid and (t-Bu)₂PCl is described. The byproduct m-chlorobenzoic acid is neutralized by addition of Et₃N. Complex 1 crystallizes in the monoclinic space group P2₁/c (No. 14), with a = 5.9637(2) Å, b = 11.4734(4) Å, c = 16.2400(5) Å and β = 107.7160(14).     

A Convenient One-Pot Synthesis of 1,2-Aminoalcohols

We have developed a rapid facile synthesis of 1,2-aminoalcohols from a variety of aldehyde starting materials. This one pot synthesis proceeds via the in situ formation of cyanohydrin trimethylsilyl ethers and the subsequent addition of Grignard reagents. This method is of particular use where the initial aldehyde exhibits water solubility.     

A Convenient One-Pot Synthesis of Symmetric Secondary and Tertiary Vicinal Diamines

A convenient one-pot synthesis of symmetric vicinal diamines utilizing sodium borohydride/trifluoroacetic acid reduction methodology is described .     

One-Pot Synthesis of Mannich Bases Under Solvent-Free Conditions

A mild and practically convenient one-pot procedure for the Mannich reaction via condensation of amines, aldehydes and malonates, β-ketoesters, or β-dicarbonyl compounds has been carried out without using any organic solvent, metallic catalyst, or Lewis acids or bases at room temperature. The present protocol offers several advantages, such as goods yields, simple procedure with easy workup, and the absence of any volatile, hazardous organic solvents and metallic catalyst.