Synthesis and Antibacterial Studies of Some Novel 2-(Coumarin-3-yl)-5-mercapto-1,3,4-oxadiazoles Containing 2,4,6-Trisubstituted s-Triazine Derivatives

A new series of 2-(coumarin-3-yl)-5-mercapto-1,3,4-oxadiazoles based on various aryl thiourea/ureas incorporating a 1,3,5-s-triazine moiety is reported. The components of this series have been obtained by the reaction of cyanuric chloride (1) with 2-(coumarin-3-yl)-5-mercapto-1,3,4-oxadiazole (2). The prepared 2-{(coumarin-3-yl-1,3,4-oxadiazolyl)-5-thio}-4,6-dichloro-s-triazine (3) was subsequently treated with morpholine (4) to form 2-{(coumarin-3-yl-1,3,4-oxadiazolyl)-5-thio}-4-(morpholino)-6-chloro-s-triazine (5). This was further treated with various substituted aryl urea/thioureas (6a–k/7a–k) to afford the title compounds 8a–k and 9a–k, which were and tested for their antibacterial activity (MIC) against different microorganisms. The structures of the novel synthesized compound have been established on the basis of ¹H NMR and FT-IR data together with elemental analysis.

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.     

THE REACTION OF TERMINAL PHOSPHINIDENE COMPLEXES WITH ELECTRON-RICH ALKYNES: A NEW APPROACH TO THE PHOSPHOLE RING

Abstract

The reaction of electron-rich alkynes such as ethoxyacetylene or propynyldiethylamine with a transient terminal phosphinidene complex such as [PhP?W(CO)₅] directly yields the corresponding phosphole complexes via a formal [2 + 2 + I] cycloaddition involving two molecules of alkyne and one phosphorus center.     

Generation of Phosphide Anions from Phosphorus Red and Phosphine in Strongly Basic Systems to Form Organylphosphines and -Oxides

Abstract

Generation of phosphide anions from phosphorus red or phosphine under the action of strong bases followed by their reactions with organyl halides, electrophilic alkenes and alkynes proves to be the most straightforward and well-controlled route to mono-, di- or triorganylphosphines or phosphine oxides of diverse structure.     

CONFORMATIONAL INVESTIGATION OF SOME SYMMETRICALLY SUBSTITUTED DIALKYL MONO-SULFIDES AND DISULFIDES BY IR SPECTROSCOPY

Abstract

Several infrared and Raman studies have been performed on compounds containing the disulfide group in the region of C-S and S-S stretching modes (1–4) in order to get a better insight of the correlations between molecular conformation and peculiar geometry parameters of the dihedral angle CS-SC.     

Microwave‐Assisted Construction of Diaryl Ethers Directly from Arylmethanesulfonates as Convenient Latent Phenols with Aryl Halides

The microwave‐assisted synthesis of diaryl ethers directly from aryl halides and arylmethanesulfonates, which as latent phenols obviate a deprotection step prior to the S_NAr reaction, in the presence of Cs₂CO₃ is described. The reaction time was very short (6–9 min), and good to excellent yields (53–90%) with the wide substrate scope were achieved without any catalyst.     

Synthesis and Electrophilic Cyclization Reactions of Diphenyl 3-Methylpenta-1,2,4-trienyl Phosphine Oxide

Diphenyl 3-methyl-penta-1,2,4-trienyl phosphine oxide can be readily prepared via an atom-economical [2,3]-sigmatropic rearrangement of the mediated alkenynyl phosphinite formed in situ by reaction of 3-methylpent-1-en-4-yn-3-ol with diphenylchlorophosphine. Electrophilic cyclization reactions of the vinylallenyl phosphine oxide prepared were investigated as it was established that the reactions proceeded with formation of various heterocyclic or highly unsaturated compounds with participation of the allenic and/or 1,3-dienic part of the vinylallenic system with neighboring group participation of phosphoryl and/or vinylic group.

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Synthesis of Aromatic Aldehydes by a Fast Method Involving Kornblum's Reaction

Aromatic aldehydes were synthesized by oxidation of corresponding halides with dimethyl sulfoxide on potassium bicarbonate by microwave irradiation. Short reaction time and high yields were obtained.     

Stereoselective Synthesis of (Z)‐ and (E)‐Allyl Aryl Sulfides and Selenides from Baylis?Hillman Acetates under Neutral Conditions Using β‐Cyclodextrin in Water

The first example of the stereoselective synthesis of (Z)‐ and (E)‐allyl aryl sulfides and selenides from Baylis? Hillman acetates under neutral conditions in H₂O by supramolecular catalysis involving β‐cyclodextrin is reported. β‐Cyclodextrin can be recovered and reused. The reaction is very efficient in providing allyl aryl sulfides and selenides in good‐to‐excellent yields with clean reaction profiles under mild reaction conditions.     

Diammonium Hydrogen Phosphate as a Neutral and Efficient Catalyst for Synthesis of 1,8‐Dioxo‐octahydroxanthene Derivatives in Aqueous Media

A new and efficient method to synthesize a 3,3,6,6,9‐aryl‐1,8‐dioxo‐octahydroxanthene derivative using diammonium hydrogen phosphate as catalyst was performed in water at room temperature in a short periods.     

Odorless Preparation of Thioglycosides and Thio‐Michael Adducts of Carbohydrate Derivatives

A general, odorless, one‐pot methodology has been developed for the preparation of 1,2‐trans‐thioglycosides and thio‐Michael addition products of carbohydrate derivatives through triphenyl phosphine‐mediated cleavage of disulfides and reaction of the thiolate formed in situ with glycosyl bromides and glycosyl conjugated alkenes.