The Synthesis of Novel S-, S,S-, S,S,S-, and N,S-Substituted Nitrodienes from Polyhalonitrodienes and Thiols

Abstract

The novel S-, S,S-, and S,S,S-substituted nitrobutadienes were synthesized from the reactions of 2-nitrobutadiene compounds with some thiols. The new N,S-substituted nitrobutadienes were obtained from the reaction of the mono-thiosubstituted butadienes with morpholine, thiomorpholine, homopiperazine, and piperazine derivatives. The structures of new compounds were determined by spectroscopic techniques.

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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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Reaction of 5-Substituted tetrazoles with trifluoroacetic anhydride

5-Substituted tetrazoles readily react with trifluoroacetic anhydride at 20–25°C to give the corresponding 2-substituted 5-trifluoromethyl-1,3,4-oxadiazoles, in contrast to published data according to which the title compounds are converted into 1,3,4-oxadiazole derivatives on heating with carboxylic acid anhydrides or chlorides at 100–120°C. The reaction is governed not only by the rate of acylation of the tetrazole ring and temperature conditions but also by the stability of intermediate N-acyltetrazoles.     

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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The Mechanisms of Acid-Catalyzed Hydrolysis of N-(4-Substituted Arylthio) Phthalimides

Abstract

The acid-catalyzed hydrolysis of N-(4-substitutedarylthio)phthalimides was studied in aqueous solutions of sulfuric, perchloric, and hydrochloric acids at 40.0 ± 0.1 °C. Analysis of the data by the excess acidity method, activation parameters, and substituent effects indicates hydrolysis by an A-2 mechanism at low acidity. At higher acidities, a changeover to an A-1 mechanism is observed.

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Reaction of 1-Aryl-1H-1,2,3-Triazole-4-Carbonyl Chlorides/Isothiocyanates with 3-Amino-5-Methylisoxazole

Abstract

1-Aryl-1H-1,2,3-triazole-4-carbonyl chlorides were selected as starting materials for the Boulton–Katritzky rearrangement. When 3-amino-5-methylisoxazole was acylated by 1-aryl-1H-1,2,3-triazole-4-carbonyl chlorides, 1-aryl-5-methyl-N-(5-methylisoxazol-3-yl)-1H-1,2,3-triazole-4-carboxamides 5 were obtained and no further rearrangement occurred. On the other hand, when 1-aryl-1H-1,2,3-triazole-4-carbonyl chlorides were first converted into isothiocyanates by the reaction with KSCN and then were allowed to react with 3-amino-5-methylisoxazole 4 in one pot, intermediate thioureas were formed and spontaneously transformed in statu nascendi into 1,2,4-thiadiazole derivatives 6.

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Synthesis of Spiroheterocycles Containing Thiadiazole Thiadiazine and Triazine Moieties from Nitrilimines

Abstract

A series of 5-substituted 1-methyl-3-phenyl-4,5-dihydro-1,2,4-triazin-6-ones was prepared by the reaction of α-amino acid methyl esters with appropriate nitrilimines and treated with phosphorus pentasulfide to afford 5-substituted 1-methyl-3-phenyl-4,5-dihydro-1,2,4-triazin-6-thiones. When 1,2,4-triazin-6-thiones were allowed to react with nitrilimine, the novel 4,6-dimethyl-2,8-di-phenyl-10-substituted-1-thia-3,4,6,7,9-pentaazaspiro[4.5]dec-2,7-dienes were obtained and confirmed by their elemental analyses and spectral data. Some of the synthesized compounds were tested in vitro for their antimicrobial activity.

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Synthesis,Dimeric Crystal Structure,and Fungicidal Activity of 1-(4-Methylphenyl)-2-(5-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-4-phenyl-4H-1,2,4-triazol-3-ylthio)ethanone

Abstract

A new triazole compound, C₄₆H₄₆N₁₀O₂S₂, has been synthesized, and the crystal structure was determined by a single crystal X-ray diffraction study. The fungicidal activity of the title compound was determined, and the results showed that it displays moderate fungicidal 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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Planar Chiral and Achiral Arenido(triphenylphosphane)nickel(II) Complexes Containing N,O Bidentate Ligands: 19F, 1H,and 31P NMR Studies

Abstract

Planar chiral and achiral arenido(triphenylphosphane)nickel(II) complexes (arenido = mesitylenido, 2-toluenido) comprising electronically delocalised N,O chelating ligands were studied by ¹H and ¹⁹F NMR using 1D and 2D techniques. Results from complexes and corresponding ligands are discussed in the light of molecular structures obtained from X-ray diffraction.

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Succinimide-N-Sulfonic Acid: A Mild,Efficient, and Reusable Catalyst for the Chemoselective Trimethylsilylation of Alcohols and Phenols

Abstract

Succinimide-N-sulfonic acid (SuSA) is easily prepared by the reaction of succinimide with chlorosulfonic acid. This reagent is able to efficiently catalyze the chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS). All reactions were performed under mild reaction conditions, giving excellent yields.

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Solvent-Free,Efficient, and High Regioselective Conversion of Epoxides to Symmetrical and Unsymmetrical vic-Dihalides Using Chlorodiphenylphosphine and N-Halosuccinimides

Abstract

A new method is described for the efficient and high regioselective conversion of epoxides to symmetrical and unsymmetrical vic-dihalides in high yields using chlorodiphenylphosphine and N-halosuccinimides under solvent-free and neutral conditions and at room temperature.

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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