Reaction of 3-Arylmethylidene-3H-furan-2-ones with 3-Amino-1,2,4-triazole as a Convenient Technique to Synthesize Condensed Diazepinones

The interaction of the arylmethylidene derivatives of 3H-furan-2-ones with 3-amino-1,2,4-triazole was studied. The structure of the final products depends on reaction conditions and reagent ratio.

Silica Sulfuric Acid,an Efficient and Recyclable Solid Acid Catalyst for the Synthesis of 4,4′-(Arylmethylene)bis (1H-pyrazol-5-ols)

Silica sulfuric acid (SSA) is employed as a recyclable catalyst for the condensation reaction of aromatic aldehydes with 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction is performed in a mixture (1:1 v/v) of water–ethanol at 70 °C, giving 4,4′-alkylmethylene-bis(3-methyl-5-pyrazolones) in 75–93% yields.

Reductive Studies on 3-Oxidopyrylium-alkene [5 + 2] Cycloadducts: Access to Some Hydroxy Cycloheptenoids

The scope of nickel boride as a versatile reducing reagent is extended to the 3-oxidopyrylium-alkene [5 + 2] cycloadducts. In this report, we demonstrate that nickel boride is capable of one-pot 1,2- and 1,4-reduction of enones present in the cycloadducts in good yields. Subsequent elaboration of the cycloadducts towards synthesis of functionalized cycloheptenoid derivatives devoid of the oxa-bridge is also explored.

Improved Synthesis of Monoprotected 5- and 6-Amino-2-azanorbornanes

An improved synthesis of Boc-monoprotected 5- and 6-amino-2-azanorbornanes is reported. The synthetic scheme consists of five steps and allows multigram quantities of the title compounds to be obtained. The regio- and stereochemistries of the products are established by two-dimensional NMR experiments.

Basic Ionic Liquid as Catalyst for the Efficient and Green Synthesis of 2-Amino-3-nitrobenzonitriles in Ethanol

A basic ionic liquid, [BmIm]OH was used as catalyst in the cyclocondensation of various kinds of vinylmalononitriles with nitroolefins in ethanol at reflux. A series of 2-amino-3-nitrobenzonitriles were obtained in reasonable yields. The straightforward and green protocol was found to be fairly efficient, and the catalyst could be recycled and reused in subsequent reactions with consistent activity. The mechanism of the reaction was discussed.

Novel Synthetic Routes of 3-Methoxypropanal from Glycerol

A new synthesis of 3-methoxypropanal from glycerol was presented. With this new approach, the conversion of glycerol to 3-methoxypropanal can be effected in moderate yield using catalysts of copper sulfate and polyethylene glycol (PEG).

Facile Synthesis of Spiro Oxindoles,Azaoxindoles, and Dihydroisoquinolone

Formation of 1-aryl-4-oxo-cyclohexa(e)nonecarboxylates from the Diels–Alder cycloaddition of 2-trimethylsilyloxy-1,3-butadiene and Danishefsky diene with aryl- and pyridylacrylates and further conversion thereof to spirocycles is described. This provides an efficient method for spiro oxindoles, azaoxindoles, and dihydroisoquinolones.

Efficient Synthesis of 3-Methyl-2H-chromen-2-one: Classic Versus Microwave Conditions

The reaction of salicylaldehyde with propionic anhydride in the presence of anhydrous K₂CO₃ as catalyst afforded 3-methyl-2H-chromen-2-one (3-methylcoumarin) in good yields depending on the reaction conditions. The reaction was performed under classic thermal (55% yield) and microwave conditions (91–97% yield).

Ammonium Chloride–Catalyzed One-Pot Synthesis of Tetrahydrobenzo[α]xanthen-11-one Derivatives Under Solvent-Free Conditions

A one-pot, multicomponent reaction of aldehydes, dimedone, and β-naphthols is described for the preparation of 12-aryl- or 12-alkyl-8,9,10,12-tetrahydrobenzo[α]xanthen-11-one derivatives using ammonium chloride as a mild, inexpensive, and environmentally benign catalyst under solvent-free conditions. Different types of aldehyde and β-naphthol derivatives are used in the reaction, and in all cases the products were synthesized successfully.

One-Pot Synthesis of 2-Amino-5,10-dihydro-5,10-dioxo-4-phenyl-4H-benzo[g]chromene Derivatives Catalyzed by ZnCl2

An efficient one-pot synthesis of 2-amino-5,10-dihydro-5,10-dioxo-4-phenyl-4H-benzo[g]chromene derivatives has been achieved by the reaction of 2-hydroxynaphthalene-1,4-dione, cyanothioacetamide, and aromaticaldehyde in EtOH at room temperature catalyzed by ZnCl₂. The structures of the products were characterized by infrared, ¹H NMR, mass, and elemental analysis.

Deoxygenation of Aromatic Ketones Using Transfer Hydrogenolysis with Raney Nickel in 2-Propanol

Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol.

Simple and Efficient One-Pot Synthesis of Nitriles from Amides and Oximes Using in Situ–Generated Burgess-Type Reagent

The dehydration of aldoximes and amides, and oxidation of benzoin are accomplished in one-pot using in situ–generated Burgess-type reagent.

Palladium-Catalyzed N-Arylation of 3-Functionalized 2-Amino-4,5-dimethylpyrroles

A versatile class of 2-aminopyrroles containing various electron-withdrawing substituents at the 3-position have been N-arylated on the amine using a palladium-catalyzed cross-coupling reaction. Using this methodology, a pyrimidone-based tricyclic system has been prepared in just one step from a starting 2-aminopyrrole.

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.

Use of Magnesium (Turnings) as a Powerful Catalyst for the O-Acylative Cleavage of Tetrahydrofuran

In a short reaction time, acyl chlorides and dry tetrahydrofuran react in the presence of a catalytic amount of magnesium turnings (Mg) at 25 °C to give 4-chlorobutyl esters in excellent yields.

Solvent-Free Amination of Secondary Benzylic Alcohols with N-Nucleophiles Catalyzed by FeCl3

A general, simple, and environmentally friendly method for the direct amination of secondary benzyl alcohols with amides or 4-nitroaniline is described. This method has been applied to a variety of substrates, and the reaction proceeded smoothly at room temperature under solvent-free conditions. CbzNH₂ was proved to be very useful in the direct preparation of the benzylic amines from corresponding alcohols.

Facile and Efficient Method for the Synthesis of 14-Substituted-14-H-dibenzo[a,j]xanthenes Catalyzed by Ruthenium Chloride Hydrate as a Homogeneous Catalyst

Synthesis of dibenzoxanthenes through condensation of β-naphthol with various aromatic and aliphatic aldehydes in ethanol as an ecofriendly solvent using Ru^III as catalyst is reported.

Synthesis and Characterization of New 2-Oxo-azetidine Derivatives

Several new N-[(4-aryl-3-chloro-2-oxo-azetidine)acetamidyl]-5-nitroindazoles 4a–l were synthesized from N-(arylidene amino acetamidyl)-5-nitroindazoles 3a–l. The structures of all these compounds were confirmed by infrared, ¹H NMR, ¹³C NMR, and fast atom bombardment–mass spectra and also by microanalytical data.

Highly Efficient One-Pot Synthesis of 2-Aminobenzoxazoles Using Triflic Acid as a Cyclodesulfurizing Reagent

An efficient one-pot synthetic strategy for 2-aminobenzoxazoles was developed from isothiocyanates and 2-aminophenol using triflic acid as a cyclodesulfurizing reagent.

Synthesis of 4-Methylene-1,3-naphthoxazines by the Reaction of Imines with Triphosgene

Reaction of 2-acetyl-1-naphthol with aliphatic amines under microwave irradiation gave the corresponding imines (Schiff bases), which were treated with triphosgene to give 4-methylene-1,3-naphthoxazines in good yields.