Synthesis and Bioassay of Ethyl-2- (2-((Diethoxyphosphoryl) (Aryl) Methylamino)Thiazol-4-Yl)-2-(Methoxyimino)Acetates

Abstract

A simple, efficient, and environmentally benign methodology has been accomplished for the synthesis of α-aminophosphonates by one-pot three-component reaction of ethyl-2-amino-α-(methoxy-imino)-4-thiazoleacetate, aldehydes, and diethylphosphite by using Amberlyst-15 as catalyst at room temperature under solvent-free conditions. Their chemical structures were characterized by infrared (IR), NMR (¹H, ¹³C & ³¹P), mass spectral, and elemental analysis. All the title compounds were screened for radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitic oxide (NO), and hydrogen peroxide (H₂O₂) methods.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.     

Green Enzymatic Synthesis of L-Ascorbyl Fatty Acid Ester: An Antioxidant

In green chemistry, biocatalysis using microwaves is a very attractive tool for various regioselective syntheses. L-Ascorbyl fatty acid esters were synthesized by an immobilized lipase from Bulkholderia multivorans using microwaves, with a dynamically enhanced rate of reaction and appreciable yield of around 80%. Microwave radiation had no effect on enzymic inactivation, however, synergism between microwaves and biocatalyst was observed.     

Facile Synthesis and Unusual Methanesulfonylation Reaction of (2R,3R)‐1,4‐Dimethoxy‐1,1,4,4‐tetrasubstituted‐2,3‐butanediols

A facile method for the synthesis of (2R,3R)‐1,4‐dimethoxy‐1,1,4,4‐tetrasubstituted‐2,3‐butanediols involving oxidative cleavage of benzylidene acetal as a key step is described. These sterically hindered diols unusually formed cyclic sulfites as the major product under methanesulfonylation reaction conditions.     

Micron Particles of AlN/Al: Efficient,Novel, and Reusable Heterogeneous Catalyst for the Synthesis of Bis(indolyl)methanes

The present work introduces for the first time the catalytic utility of micron particulate aluminium nitride (AlN/Al) as a novel and reusable heterogeneous catalyst for the synthesis of bis(indolyl)methanes involving the electrophilic substitution of indoles on aldehydes. The catalyst is recyclable and works without any significant change in its catalytic activity.     

Lanthanum(III) Nitrate Hexahydrate: A Versatile Reagent for the Synthesis of Bis(indolyl) Methanes under Solvent‐Free Conditions

A mild and efficient synthesis of bis(indolyl) methanes by the reaction of indoles with various aldehydes at room temperature in the presence of a catalytic amount of a La(NO₃)₃ · 6H₂O afforded the corresponding bis(indolyl) methanes in excellent yields under solvent‐free conditions.     

A Clean and Expedient Synthesis of Pyrido[1,4]oxazepino Spiropyrrolidines Through One-Pot,Three-Component [3 + 2] Cycloaddition Reaction

One-pot three component synthesis of novel pyrido[1,4]-oxazepine fused spiropyrrolidines has been accomplished in good yields by 1,3-dipolar cycloaddition reaction of azomethine ylide, derived from paraformaldehyde and sarcosine with (E)-4-benzylidene-hexahydro-1H-pyrido[2,1-c][1,4]-oxazepine-3(7H)-one as dipolarophiles derived from Baylis-Hillman adducts. The effect of solvent on the [3 + 2]-cycloaddition reaction is also studied.     

Efficient Method for Demethylation of Aryl Methyl Ether Using Aliquat-336

A rapid method for selective cleavage of aryl methylethers can be achieved in the presence of a protic acid and a catalytic amount of phase-transfer catalyst (Aliquat-336). Aliquat-336 accelerates the rate of reaction and affords the corresponding phenols in excellent to good yields on a wide variety of substrates.

[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.]     

Palladium supported on zinc ferrite: an efficient catalyst for ligand free C–C and C–O cross coupling reactions

An efficient superparamagnetic Pd–ZnFe₂O₄ solid catalyst has been synthesized by loading Pd(0) species on zinc ferrite nanoparticles. Sonogashira cross couplings between terminal alkynes and aryl halides were achieved in the absence of any Cu co-catalyst. A Heck–Matsuda coupling reaction of structurally different aryldiazonium tetrafluoroborate substrates was preceded at 40 °C in water. Cyanation of aryl halides was successfully done using K₄[Fe(CN)₆] as the cyanide source over Pd–ZnFe₂O₄. The catalyst was also employed for Ullmann type cross coupling reactions. Excellent yield of the products, reusability, and uncomplicated work-up make this catalyst efficient for C–C and C–O coupling reactions. Good yield of products, easy separation, and negligible leaching of Pd from the catalyst surface confirm the true heterogeneity in these catalytic reactions.     

Hydrothermal conditions on Sn0.95Co0.05O2: nanostructures, ferromagnetism and optical behavior

We have studied the effect of hydrothermal conditions at constant temperature of 180 °C, varying preparation time for 15, 30 and 45 h on nanostructures of diluted magnetic semiconductor Sn_0.95Co_0.05O₂ (SC5). X-ray diffraction pattern confirm the tetragonal SnO₂ rutile phase. The transmission and scanning electron microscopy shows the resulting nanostructures i.e. nanospheres and nanorods. The proposed reaction mechanism is given. The Raman spectra show the formation of tetragonal rutile structure of SC5 nanostructures. Fourier transform infrared spectrum has been used to verify the existence of Sn–O bond. The photoluminescence spectra show that the emission spectral intensity increases gradually with decreasing grains size, increasing hydrothermal heating time of SC5 samples and exhibits an intense blue luminescence centered at a wavelength of 531 nm. The optical absorbance measurements revealed that the nanometric size of the materials influences the energy band gap. All the prepared SC5 samples exhibit room temperature ferromagnetism.