Synthesis and Spectral Characterization of Some Novel Thiazolyl-Pyrazoline Derivatives Containing 1,2,3-Triazole Moiety

Abstract

A series of novel 3-aryl-5-(2-aryl-1,2,3-triazol-4-yl)-1-(4-aryl-2-thiazoyl)-pyrazolines 6a–6r were synthesized using 2-aryl-4-formyl-1,2,3-triazoles 1a,b as the starting materials. Thus, reacting 1a,b with 1-arylethanones 2a–2c gave 1-aryl-3-(2-aryl-1,2,3-triazol-4-yl)-2-propen-1-ones 3a–3f. The reaction of the latter with thiosemicarbazide afforded 3-aryl-5-(2-aryl-1,2,3-triazol-4-yl)-1-thiocarbamoyl-pyrazolines 4a–4f, which condensed with 2-bromo-1-arylethanones 5a–5c to afford the target compounds 6a–6r. The chemical structures of the compounds were verified by means of their IR, ¹H NMR, ESI-MS spectroscopic data, and 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.

GRAPHICAL ABSTRACT     

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 and Spectroscopic Evaluation of Novel N-, S-, and O-Substituted 1,4-Naphthoquinone Derivatives

Abstract

Novel O- S,O- S,S- N,N- and N,S-substituted naphthoquinone compounds were prepared by reaction of 2,3-dichloro-1,4-naphthoquinone and the corresponding nucleophiles in the presence of chloroform and triethylamine or ethanol solution of Na₂CO₃. The structures of the novel naphthoquinone compounds were characterized by micro analysis, FT-IR, UV/Vis, ¹H NMR, ¹³C NMR, MS, and fluorescence spectroscopy.

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N-(Diphenoxyphosphoryl)Succinimide: Synthesis and Reaction with Alkoxides

Abstract

Reaction of succinimide with diphenylchlorophosphate in the presence of lithium bis(trimethylsilyl)amide followed by aqueous work-up led to the formation of amidophosphate 3. The same reaction performed in the presence of sodium hydride yield N-(diphenylphosphoryl)succinimde 4, which undergoes nucleophilic ring opening with sodium alkoxides resulted in the formation of phosphoroamidate analogues 5 a-d in good yields.

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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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Synthesis and Characterization of Novel Quinazoline-Substituted 1,3,4-Thiadiazolium-5-thiolates

Abstract

Novel 3-[4-(6-bromo-4-oxo-2-phenylquinazolin-3(4H)-yl)benzoyl]-2-substituted-1,3,4-thiazolium-5-thiolate 7(a–j) and 3-{4-[(6-bromo-2-phenylquinazolin-4-yl)amino] benzoyl}-2-substituted-1,3,4-thiadiazolium-5-thiolate 12(a–j) were synthesized from 6-bromo-2-phenyl-4H-3,1-benzoxazin-4-one (1). The structures of the newly synthesized compounds were confirmed by spectral data and 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.

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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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Synthesis and Characterization of [1,2,4,6]Thiatriazino[2,3-a][1,3]benzimidazol-1(2H)-one and [1,3,5]Thiadiazino[3,4-a][1,3]benzimidazol-2-imine

Abstract

The reaction of thionyl chloride with amidines 2, derived from N-benzimidazol-2-yl imidates 1, leads to [1,2,4,6]thiatriazino[2,3-a][1,3]benzimidazol-1(2H)-one 3 in good yields. [1,3,5]Thiadiazino[3,4-a][1,3]benzimidazol-2-imine 4 was prepared by condensation of NaSCN with benzimidazol-2-yl imidate 1. The isolated compounds 3 and 4 were identified by spectroscopic methods including IR, ¹H NMR, and ¹³C NMR as well as elemental analyses and MS of 3d and 4b.

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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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Reactions Between 4-Hydroxycoumarins or 4-Hydroxy-1-Methylquinolinone and Dmad in the Presence of Phosphites. Synthesis of (Chromen-3-YL)- and (Quinolin-3-YL)-(Dialkoxyphosphoryl)Succinates

Abstract

Dimethyl (chromen-3-yl)-(dialkoxyphosphoryl)succinates are prepared from the reaction of 4-hydroxycoumarin with DMAD and P(OR)₃. 4-Hydroxy-1-methylquinolinone reacts with DMAD and P(OEt)₃ to give dimethyl (quinoline-3-yl)-(diethoxyphosphoryl)-succinate.

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Poly[4-diacetoxyiodo] Styrene–Promoted Thiocyanation of Aromatic Ethers,Anilines, and Indoles

Abstract

Thiocyanation of aromatic ethers, anilines, and indoles have been achieved using ammonium thiocyanate in the presence of poly[4-diacetoxyiodo] styrene (PDAIS) in CH₃CN at room temperature.

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Microwave-Assisted Direct Synthesis of 4H-1,2,4-Benzothiadiazine 1,1-Dioxide Derivatives

Abstract

We describe a rapid and convenient methodology for the preparation of diverse 3-aryl and 3-trifluoromethyl 4H-1,2,4-benzothiadiazine-1,1-dioxides in a one-pot microwave-promoted reaction between 2-aminobenzenesulfonamides and benzaldehydes, trifluoroacetic acid or benzoic acids.

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