Microwave-Assisted Synthesis of Disulfides

Abstract

A new microwave-assisted synthesis methodology for the preparation of substituted disulfide derivatives is presented. 4-Substituted sulfenimides were reacted with 4-substituted thiols under neat (to right doughy consistency) conditions in chloroform, with both microwave heating and conventional methods. The resulting 4-substituted disulfide derivatives were obtained at higher yields and in shorter reaction times with microwave heating. Their chemistry was confirmed by ¹H-NMR, ¹³C-NMR, infrared (IR), and elemental analysis.

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Synthesis,Characterization, and Biological Screening of Some Novel Thiazolidin-4-One and α-Aminophosphonate Derivatives

Abstract

Synthesis of some new functionalized thiazolidin-4-ones and α-amino phosphonate derivatives has been reported. The imines were synthesized from the reaction of various substituted anilines with 1-phenyl-3-(pyridine-4-yl)-1H-pyrazole-4-carbaldehyde in ethanol at reflux condition. The corresponding thiazolidin-4-ones and α-aminophosphonates were prepared by reaction of imines with mercaptoacetic acid and triethyl phosphite, respectively. The structures of the newly synthesized compounds were confirmed by IR, ¹H NMR, and mass spectral data and were evaluated for their antimicrobial activities.

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One-Pot Green Synthesis of 3'-(2-Aminobenzimidazolyl)-2-Phenyl Spiro[4H-Benzopyran-4,2'-Thiazolidin]-4-Ones and Acylation Using Trifluoroacetic Anhydride

Abstract

An expeditious one-pot synthesis of a novel heterocyclic system, 3′-(2-aminobenzimidazolyl)-2-phenyl spiro[4H-benzopyran-4,2′-thiazolidin]-4-ones, has been accomplished by condensing substituted hydrazinobenzimidazole, flavanone, and mercaptoacetic acid by conventional heating in ethanol or toluene, and in an ionic liquid, viz., 1-butyl-3-methyl-imidazolium hexafluorophosphate. Excellent yields (85%–90%) and higher purity are obtained in the ionic-liquid-mediated synthesis as compared with the conventional procedure (55%–60%). Further, these compounds were acylated with trifluoroacetic anhydride. The structures of the compounds were confirmed by IR, ¹H NMR, ¹³C NMR, mass spectral data, and elemental analysis. The compounds, upon evaluation for their antibacterial, antifungal, and insecticidal activities, exhibited excellent results.

[Supplemental 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 resource: Table S1, S2, and S3]

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A Convenient Synthesis of Thiazolidin-2-ones from Thiazolidine-2-thiones: Antibiotic Activity and Revisiting the Mechanism

Abstract

Various substituted thiazolidin-2-ones were synthesized from the corresponding thiazolidine-2-thiones with bromoethanol in ethanol with sodium ethoxide as a base. The optimal reaction conditions and mechanism were reinvestigated in detail. The bioassay indicated that (S)-4-isobutyl and (S)-4-benzylthiazolidin-2-ones show certain inhibitive activities against Candida albicans and Escherichia coli.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

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Knoevenagel Condensation Catalyzed by Sodium Silicate Under Solvent-Free Conditions

Abstract

Sodium silicate pentahydrate has been utilized as an efficient catalyst for the Knoevenagel condensation of aromatic aldehydes with active methylene compounds to afford substituted olefins in yields of 80.6%～98.9% under solvent-free conditions at room temperature within a short time. The advantages of this procedure are mild reaction conditions, excellent yields, cleaner reaction profiles, and operational simplicity.

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Crystal Structure and Spectroscopic Properties of (2-oxo-2H-chromen-3-yl)phosphonic Acid Monoethyl Ester Trihydrate

Abstract

(2-Oxo-2H-chromen-3-yl)phosphonic acid monoethyl ester trihydrate (1) was synthesized, isolated, and spectroscopically as well as structurally characterized by means of single crystal X-ray diffraction; conventional and linear-polarized IR spectroscopy; electronic (UV-VIS-NIR) spectroscopy; ¹H, ¹³C, and ³¹P NMR. Quantum chemical DFT calculations have been performed in order to obtain information on the electronic structure and vibrational properties of 1, thus supporting the experimental data. The correlation between the structure and spectroscopic characteristics is discussed.

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Synthesis of New Benzylic Di-, Tri-, and Tetraphosphonic Acids as Potential Chelating Agents

Abstract

New di-, tri-, and tetraphosphonic acids were synthesized starting from four o-hydroxymethyl phenol derivatives and obtained in three steps in good overall yield. The phosphonic acids were isolated and purified using semi-preparative C₁₈ HPLC column. The new compounds were characterized using different spectroscopic methods (¹H, ¹³C, and ³¹P NMR; ESI MS; and MSⁿ, IR).

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New Routes to β-Iminophosphonates,Phosphineoxides, and Sulfides

Abstract

Two synthetic methods leading to β-iminophosphonates, phosphineoxides, and sulfides 2 are reported. The first method involves the reaction of imines with chlorophosphines and phosphites followed by oxidation or sulfurization. The second one utilizes the reaction of imines with diethylchlorophosphate and thiophosphate. The stereochemistry of the obtained products is discussed, and their structure is confirmed by NMR (¹H, ³¹P, ¹³C) and IR spectroscopies, and by mass spectrometry.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

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Regioselective Syntheses of 1-Aryl-substituted-5H-[1,3]thiazolo[3,2-a]quinazoline-5-ones During Sonogashira Coupling

Abstract

Reaction of 2-mercaptopropargylquinazoline-4-one with various aryliodides catalyzed by Pd–Cu leads to the regioselective formation of 1-arylsubstituted-5H-[1,3]thiazolo-[3,2-a]quinazoline-5-ones.

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Phase Transfer–Catalyzed,One-Pot Synthesis of Some Novel N-Pyrimidinyl-N′-nicotinyl Thiourea Derivatives

Abstract

A new series of acyl thiourea derivatives were synthesized in one-pot using PEG-600 as the phase transfer catalyst (PTC). The structures of title compounds were characterized by ¹H NMR, IR, MS, and elemental analysis. In addition, the fungicidal activity of the acyl thiourea derivatives were tested, which showed that most of them exhibit moderate activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

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An Efficient and Convenient Protocol for the Synthesis of Thiazolidin-4-Ones

Abstract

Without a catalyst and under solvent-free conditions, 2,3-disubstituted-1,3-thiazolidin-4-one 5a–j derivatives were synthesized efficiently via the three-component reaction of aryl hydrazide, aromatic aldehyde, and mercaptoacetic acid. All the newly synthesized compounds were confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy and elemental analysis.

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Phosphorylation of Dienyl Diprenoid Alcohols

Abstract

The reactions of geraniol, nerol, and linalool with N,N-diethylamido O,O-propylenephosphite and diethyl chlorophosphite were studied. On the basis of these studies, new dienyl diprenoid phosphite esters were obtained.

GRAPHICAL ABSTRACT