KI-Mediated Three-component Reaction of Hydroxylamine Hydrochloride with Aryl/Heteroaryl Aldehydes and Two β-Oxoesters

A KI-mediated multi-component cyclocondensation of hydroxylamine hydrochloride, aromatic/hetero-aromatic aldehydes, and   ethyl acetoacetate or 4-chloroethyl acetoacetate to form isoxazole-5(4H)-one heterocycles is described. The reaction employs readily accessible starting reactants and provides a range of synthetically isoxazole-5(4H)-ones in good to high yields. Reactions were performed in water as a green medium at room temperature (RT) without heating, microwave irradiation or sonication.  Reusability of the reaction medium is also a noteworthy characteristic of this reaction. DOI: http://dx.doi.org/10.17807/orbital.v10i2.113

Green and three-component synthesis of isoxazolones using natural sunlight and investigating their antibacterial activity

The green and efficient three-component reaction between aromatic and heteroaromatic aldehydes, β-ketoesters (ethyl acetoacetate and ethyl benzoylacetate) and hydroxylamine hydrochloride in water and under natural sunlight leads to the formation of various derivatives of 4-arylidene-isoxazole-5(4H)-ones. In this reaction, natural sunlight was used outdoors as a green, cheap, clean, available, safe and non-toxic source of energy. The reactions were carried out in Damghan under sunlight. In this synthetic method using sunlight, the heterocyclization reaction was performed with simple tools and without the use of special equipment. In this three-component reaction, 4-arylidene-isoxazole-5(4H)-ones were synthesized in a range of 17-40 minutes and with yields ranging from 89-97%. The advantages of this suitable and green method can be mentioned abundant sunlight or low-energy visible light as an energy source, no environmental pollution, very mild reaction conditions, simplicity of the reaction method, easy separation, no use of organic solvents and catalysts. Some compounds were tested for antibacterial activity using Staphylococcus aureus and Escherichia coli by disk diffusion method. Some synthesized compounds have good antibacterial activity. The antibacterial activity of synthesized heterocycles is higher against Escherichia coli

Starch-derived magnetic nanoparticles (Fe3O4@C-SO3H): Synthesis, Characterization and Its application on the preparation of dihydropyrano[c]chromenes, 2‑Amino-3-cyano‑4H‑pyrans and 2-amino-4H-chromenes derivatives

In this study, a novel biomass and Starch-derived carbonaceous solid acid catalyst (Fe3O4@C-SO3H) that has superparamagnetism with high acid density was successfully prepared for the first time by incomplete hydrothermal carbonization of Starch followed by Fe3O4 grafting and –SO3H groups functionalization. The characterization of physicochemical properties of Fe3O4@C-SO3H NPs was achieved by X-ray diffraction (XRD), Fourier-transform infrared spectra (FT-IR) and Field Emission scanning electron microscope (FESEM). The resulted catalyst contained -SO3H, -COOH, and phenolic -OH groups and exhibited good catalytic activity for the one-pot synthesis of dihydropyrano[c]chromenes, 2‑Amino-3-cyano‑4H‑pyrans and 2-amino-4H-chromenes derivatives (chromenes and pyrans) via multicomponent reactions. High catalytic activity and easy magnetical separation from the reaction mixture are two significant factors for evaluating the performance of Fe3O4@C-SO3H nanoparticles in the organic transformations

A catalytic three-component synthesis of isoxazol-5(4H)-ones under green conditions

515-520The three-component cyclocondensation of various aryl/heteroaryl aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/ethyl 4-chloro-3-oxobutanoate have been established for the synthesis of isoxazol-5(4H)-ones using sodium malonate as an efficient catalyst. This reaction has been performed in water as a green reaction medium at 25°C. Optimization of the reaction conditions show that the reaction performs better in aqueous medium, at room temperature, and in the presence of 10 mol% of the catalyst. This procedure has several unique features, including shorter reaction times, easy separation of pure products, avoiding the hazardous organic solvents, simplicity of experimental procedures, operationally simple, and eco-friendly

KI-Mediated Three-component Reaction of Hydroxylamine Hydrochloride with Aryl/Heteroaryl Aldehydes and Two β-Oxoesters

A KI-mediated multi-component cyclocondensation of hydroxylamine hydrochloride, aromatic/hetero-aromatic aldehydes, and   ethyl acetoacetate or 4-chloroethyl acetoacetate to form isoxazole-5(4H)-one heterocycles is described. The reaction employs readily accessible starting reactants and provides a range of synthetically isoxazole-5(4H)-ones in good to high yields. Reactions were performed in water as a green medium at room temperature (RT) without heating, microwave irradiation or sonication.  Reusability of the reaction medium is also a noteworthy characteristic of this reaction. DOI: http://dx.doi.org/10.17807/orbital.v10i2.1134 </p

Salicylic Acid-catalyzed Three-component Synthesis of 1-Amido/thioamidoalkyl-2-naphthols Under Solvent-free Conditions

A simple, efficient, and green procedure for the solvent-free synthesis of 1-amido/thioamidoalkyl-2-naphthols by one-pot stirring of starting reactants at 100 °C has been introduced. By utilizing salicylic acid (SA) as the catalyst, the reaction of aryl aldehydes, 2-naphthol, and acetamide/benzamide/urea/thiourea were successfully performed, and 1-amido/thioamidoalkyl-2-naphthols were obtained in good to high isolated yields. The notable advantages of this method over some previous methods are the availability of catalyst, atom efficiency, not using any solvent for reaction, relatively green conditions, no need for catalyst synthesis, relatively shorter reaction times, and no specialized equipment (microwave or ultrasound) or purification techniques are needed. DOI: http://dx.doi.org/10.17807/orbital.v11i1.1355 </p

A catalytic three-component synthesis of isoxazol-5(4H)-ones under green conditions

The three-component cyclocondensation of various aryl/heteroaryl aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/ethyl 4-chloro-3-oxobutanoate have been established for the synthesis of isoxazol-5(4H)-ones using sodium malonate as an efficient catalyst. This reaction has been performed in water as a green reaction medium at 25°C. Optimization of the reaction conditions show that the reaction performs better in aqueous medium, at room temperature, and in the presence of 10 mol% of the catalyst. This procedure has several unique features, including shorter reaction times, easy separation of pure products, avoiding the hazardous organic solvents, simplicity of experimental procedures, operationally simple, and eco-friendly

N-(4-(6-(4-nitrophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-ene-2-yl)phenyl)acetamide

As a result of three-component one-pot reaction of trans-2-benzoyl-3-(4-nitrophenyl)aziridine with 4-acetamidobenzaldehyde and ammonium acetate, N-(4-(6-(4-nitrophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-ene-2-yl)phenyl)acetamide was obtained in good yield. The newly synthesized compound exhibit interesting photochromic behavior in the solid and solution state. The structure of the synthesized compound was confirmed by elemental analysis, 1H-NMR, 13C-NMR and UV-Visible spectral data

2-(4-Diethoxymethylphenyl)-6-(4-nitrophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-ene

The photochromic compound was obtained from 4-diethoxymethyl-benzaldehyde and trans-2-benzoyl-3-(4-nitrophenyl)aziridine via a three component reaction. The structure of this compound was characterized by elemental analysis, 1H-NMR, 13C-NMR and UV-Visible spectral data

Potassium phthalimide as efficient basic organocatalyst for the synthesis of 3,4-disubstituted isoxazol-5(4H)-ones in aqueous medium

Potassium phthalimide (PPI) is employed as an efficient and effective basic organocatalyst for the one-pot three-component reaction of β-oxoesters with hydroxylamine hydrochloride and various aromatic aldehydes. This cyclocondensation reaction was performed in water as an environmentally benign solvent at room temperature giving 3,4-disubstituted isoxazol-5(4H)-ones in good to excellent yields. PPI was found to be an effective organocatalyst for the synthesis of isoxazol-5(4H)-one system. The advantages of this method are efficiency, clean, easy work-up, high yields, shorter reaction times, inexpensive, and readily available catalyst