scholarly journals Indolizines and pyrrolo[1,2-c]pyrimidines decorated with a pyrimidine and a pyridine unit respectively

2015 ◽  
Vol 11 ◽  
pp. 1079-1088 ◽  
Author(s):  
Marcel Mirel Popa ◽  
Emilian Georgescu ◽  
Mino R Caira ◽  
Florentina Georgescu ◽  
Constantin Draghici ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Steric Hindrance ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Pyridine Nitrogen Atom ◽  
Structural Isomers ◽  
X Ray ◽  
Pyridine Nitrogen

The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expected at the pyridine nitrogen atom leading to pyridinium bromides and consequently to new indolizines via the corresponding pyridinium N-ylides. However, in the case of 4-(2-pyridyl)pyrimidine the steric hindrance directs the reaction to the pyrimidinium N-ylides and, subsequently, to the formation of the pyrrolo[1,2-c]pyrimidines. The new pyrrolo[1,2-c]pyrimidines and the new indolizines were structurally characterized through NMR spectroscopy. The X-ray structures of two of the starting materials, 4-(2-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine, are also reported.

scholarly journals Diastereoselective Synthesis of Spiro[Pyrrolo[2,1-B][1,3] Benzothiazole-3,5′-[1,3]Thiazolo[3,2-B][1,2,4]Triazol]-6′-Ones via Cycloaddition Reaction of Benzothiazolium Salts

2018 ◽  
Vol 42 (7) ◽  
pp. 371-373 ◽  
Author(s):  
Qing Zeng ◽  
Demin Ren ◽  
Yulin Huang ◽  
Xinliang Fu ◽  
Xiaofang Li
Keyword(s):  
Cycloaddition Reaction ◽  
Crystallographic Analysis ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Diastereoselective Synthesis ◽  
X Ray

The 1,3-dipolar cycloaddition reaction of (Z)-5-arylidene[1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one and azomethine ylide, which was generated in situ by the reaction of N-4-methoxyphenacylbenzothiazolium bromides and triethylamine, afforded novel 2-(aryl)-1-(4-methoxybenzoyl)-1,2-dihydrospiro[pyrrolo[2,1-b][1,3]benzothiazole-3,5′-[1,3]thiazolo[3,2-b][1,2,4]triazol]-6′-ones in moderate yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS spectroscopy together with X-ray crystallographic analysis.

A Convenient Synthesis of Fused Tetrahydroazocines from Acenaphthylene-1,2-dione, Proline, and Acetylenic Esters

Synlett ◽  
2017 ◽  
Vol 29 (05) ◽  
pp. 635-639 ◽  
Author(s):  
Issa Yavari ◽  
Leila Baoosi ◽  
Mohammad Halvagar
Keyword(s):  
Cycloaddition Reaction ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
X Ray Diffraction ◽  
Acetylenic Esters ◽  
X Ray ◽  
Convenient Synthesis ◽  
Boat Form ◽  
Twist Boat

A synthesis of dialkyl (12E,14E)-7-oxo-10,11-dihydro-7H,9H-azocino[2,1-a]benzo[de]isoquinoline-13,14-dicarboxylates through a 1,3-dipolar cycloaddition reaction of azomethine ylides, generated in situ from proline and acenaphthylene-1,2-dione, with dialkyl acetylenedicarboxylates is described. According to the X-ray diffraction data, the tetrahydroazocine ring has a rigid twist-boat form with approximate local C2 symmetry.

scholarly journals Synthesis of 1-(2-Fluorophenyl)pyrazoles by 1,3-Dipolar Cycloaddition of the Corresponding Sydnones

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3693
Author(s):  
Denisa Dumitrescu ◽  
Sergiu Shova ◽  
Constantin Draghici ◽  
Marcel Mirel Popa ◽  
Florea Dumitrascu
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Cycloaddition Reaction ◽  
Halogen Bonding ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
Reaction Intermediates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Important Interaction

3-Arylsydnones bearing fluorine and bromine atoms on the benzene ring were synthesized from N-nitroso-2-fluorophenylglycines and characterized by NMR spectroscopy. These were employed further in synthesis of the corresponding 1-(2-fluorophenyl)pyrazoles by 1,3-dipolar cycloaddition reaction with dimethyl acetylenedicarboxylate (DMAD) as activated dipolarophile. The sydnones as reaction intermediates were characterized by single crystal X-ray diffraction analysis showing interesting features such as halogen bonding as an important interaction in modeling the crystal structure.

scholarly journals Synthesis of Dispiro[Indeno[1,2-b]Quinoxaline-11,3′-Pyrrolizine-2′,2″-[1,3] Thiazolo[3,2-a]Pyrimidine Via Cycloaddition Reactions

2018 ◽  
Vol 42 (9) ◽  
pp. 453-455 ◽  
Author(s):  
Demin Ren ◽  
Xiaolian Hu ◽  
Yulin Huang ◽  
Xiaofang Li
Keyword(s):  
Cycloaddition Reaction ◽  
Crystallographic Analysis ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
X Ray

The 1,3-dipolar cycloaddition reaction of ethyl 5-aryl-2-(2-methoxy-2-oxoethylidene)-7-methyl-3-oxo-2,3-dihydro-5 H-[1,3]thiazolo[3,2- a] pyrimidine-6-carboxylate and azomethine ylide, which was generated in situ by the reaction of 11 H-indeno[1,2- b]quinoxalin-11-one and L-proline, afforded novel 6″ethyl 1′-methyl 5″aryl-7″methyl-3″oxo-5’,6’,7’,7a′-tetrahydro-1' H,3″ H,5″ H-dispiro[indeno[1,2- b]quinoxaline-11, 3 ‘-pyrrolizine-2’,2″-[1,3]thiazolo[3,2- a]pyrimidine-1’,6″-dicarboxylates in good yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS together with X-ray crystallographic analysis.

Synthesis of Spiro[Pyrrolo[2,1-b][1,3]Benzothiazole-3,2′-[1,3]Thiazolo[3,2-a] Pyrimidine] via Cycloaddition Reactions

2018 ◽  
Vol 42 (5) ◽  
pp. 260-263 ◽  
Author(s):  
Qing Zeng ◽  
Demin Ren ◽  
Xingliang Fu ◽  
Xiaofang Li
Keyword(s):  
Cycloaddition Reaction ◽  
Crystallographic Analysis ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
X Ray

The 1,3-dipolar cycloaddition reaction of ethyl-5-aryl-2-[( Z)-2-methoxy-2-oxoethylidene]-7-methyl-3-oxo-3,5-dihydro-2 H-thiazolo[3,2- a] pyrimidine-6-carboxylates and azomethine ylide, which was generated in situ by the reaction of N-4-methoxyphenacylbenzothiazolium bromides and triethylamine, yielded novel 6′-ethyl-2-methyl-5′-aryl-1-(4-methoxybenzoyl)-7-methyl-3′-oxo-1,2-dihydro-5 H-spiro[pyrrolo[2,1- b][1,3]benzothiazole-3,2′-[1,3]thiazolo[3,2- a]pyrimidine]-2,6′-dicarboxylates in moderate yields. The structures of all of the products were characterised by NMR, IR, HRMS spectrometry, together with X-ray crystallographic analysis.

1-(2′-Benzimidazolylmethyl)-pyridinium ylide in the one-pot synthesis of indolizine and benzimidazo[1,2-a]pyridine derivatives

2015 ◽  
Vol 70 (8) ◽  
pp. 555-561 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Abdelmalek Bouraiou
Keyword(s):  
Nmr Spectroscopy ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Pyridine Derivatives ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimethyl Maleate ◽  
The One ◽  
Pyridinium Ylide

AbstractFour indolizine derivatives were obtained via 1,3-dipolar cycloaddition reaction of 1-(2′-benzimidazolylmethyl)pyridinium ylide with various electron-deficient alkynes. The reaction of this pyridinium N-ylide with dimethyl maleate gave an unexpected methyl 1-oxo-benzimidazo[1,2-a]pyridine-3-carboxylate. The structures of all reported compounds have been examined by X-ray crystallography and NMR spectroscopy.

New Pyrrolo[1,2-b]pyridazine Derivatives by 1,3-Dipolar Cycloaddition of Mesoionic Oxazolopyridazinone

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Miron Teodor Caproiu ◽  
Florea Dumitrascu ◽  
Mino R. Caira
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Pyridazine Derivatives ◽  
New Compounds

New pyrrolo[1,2-b]pyridazine derivatives 8a-f were synthesized by 1,3-dipolar cycloaddition reaction between mesoionic 1,3-oxazolo[3,2-b]pyridazinium-2-oxides and diethyl or diisopropyl acetylenedicarboxylate as alkyne dipolarophiles. The structures of the new compounds were assigned by elemental analysis and NMR spectroscopy.

scholarly journals Green ultrasound-assisted three-component click synthesis of novel 1H-1,2,3-triazole carrying benzothiazoles and fluorinated-1,2,4-triazole conjugates and their antimicrobial evaluation

2017 ◽  
Vol 67 (3) ◽  
pp. 309-324 ◽  
Author(s):  
Nadjet Rezki ◽  
Mohamed Reda Aouad
Keyword(s):  
Antimicrobial Activity ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Terminal Alkynes ◽  
One Pot ◽  
Alkyl Aryl ◽  
Antimicrobial Evaluation ◽  
Ultrasound Assisted ◽  
Click Synthesis

AbstractThe present study describes an efficient and ecofriendly, ultrasound, one-pot click cycloaddition approach for the construction of a novel series of 1,4-disubstituted-1,2,3-triazoles tethered with fluorinated 1,2,4-triazole-benzothiazole molecular conjugates. It involved three-component condensation of the appropriate bromoacetamide benzothiazole, sodium azide and 4-alkyl/aryl-5-(2-fluorophenyl)-3-(prop-2-ynylthio)-1,2,4-triazoles4a-ethrough a Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction. This approach involvesin situgeneration of azidoacetamide benzothiazole, followed by condensation with terminal alkynes in the presence of CuSO4/Na-ascorbate in aqueous DMSO under both conventional and ultrasound conditions. Some of the designed 1,2,3-triazole conjugates6a-owere recognized for their antimicrobial activity against some bacterial and fungal pathogenic strains.

scholarly journals Synthesis, Structure, and Properties of a Dinuclear Cu(II) Coordination Polymer Based on Quinoxaline and 3,3-Thiodipropionic Acid Ligands

2021 ◽  
Author(s):  
Adedibu Clement Tella ◽  
Samson Owalude ◽  
Vincent Adimula ◽  
Adetola Oladipo ◽  
Victoria Olayemi ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Coordination Polymer ◽  
Elemental Analysis ◽  
Catalytic Reduction ◽  
Copper Acetate ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr

Abstract The coordination polymer [Cu2(TDPH)4(QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90 °, β = 90.200(11) °, γ = 90 °, V = 2721.18 (2) Å3, Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu2O4N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu-Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1----Cu1 and Cu2----Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH4 in the presence of [Cu2(TDPH)4(QNX)].DMF, as catalyst was completed within 11 minutes. The 4-aminophenol product was confirmed using 1H NMR spectroscopy.

Catecholated graphene-filled polyimide with enhanced mechanical, thermal, and tribological properties

2020 ◽  
pp. 095400832094035
Author(s):  
Xing Wu ◽  
Zhengyu Jin ◽  
Yuejin Zhu ◽  
Haichao Zhao
Keyword(s):  
Friction And Wear ◽  
In Situ Polymerization ◽  
Cycloaddition Reaction ◽  
Mechanical Analysis ◽  
Dipolar Cycloaddition ◽  
Wear Properties ◽  
Comprehensive Properties ◽  
Transmission Electron ◽  
Friction And Wear Tests

In order to achieve good dispersion of graphene in polyimide (PI), catecholated graphene (G-Cat) was prepared by 1,3-dipolar cycloaddition reaction of N-methylglycine and 3,4-dihydroxybenzaldehyde with graphene sheets. G-Cat/PI composites were prepared by in situ polymerization with pyromellitic dianhydride and 4,4-oxydianiline in the presence of G-Cat. The successful modification of graphene was proved by infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy. The comprehensive properties of G-Cat/PI composites were studied by tensile, dynamic mechanical analysis, thermogravimetric analysis, and friction and wear tests. By observing the morphology of wear marks, the friction and wear properties of the composites were emphatically analyzed. Therefore, graphene/PI composites were expected to have broad application prospects in lubrication and wear resistance.

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