scholarly journals Alkylation and 1,3-Dipolar Cycloaddition of 6-Styryl-4,5-dihydro-2H-pyridazin-3-one: Synthesis of NovelN-Substituted Pyridazinones and Triazolo[4,3-b]pyridazinones

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Souad Mojahidi ◽  
Hanan Sekkak ◽  
El Mostapha Rakib ◽  
Maria G. P. M. S. Neves ◽  
Maria A. F. Faustino ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dipolar Cycloaddition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrile Imines ◽  
C Nmr

Some newN-substituted pyridazinones and triazolo[4,3-b]pyridazinones were synthesized, respectively, by simple alkylation and 1,3-dipolar cycloaddition of pyridazin-3-one with nitrile imines. The regioselectivity of the reactions was ascertained by1H,13C NMR spectroscopy and X-ray diffraction of the synthesized compounds.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

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.

The structures of indoiyl(alkoxy)carbenium tetrafluoroborates: a new class of highly stabilized carbenium ions

1989 ◽  
Vol 44 (6) ◽  
pp. 659-665 ◽  
Author(s):  
Ulf Pindur ◽  
Ludwig Pfeuffer ◽  
Camran Flo ◽  
Werner Massa ◽  
Karin Seitz
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Crystalline State ◽  
X Ray Diffraction ◽  
Carbenium Ions ◽  
X Ray ◽  
Axial Chirality ◽  
New Class ◽  
Charge Distributions ◽  
C Nmr

The conformations of and charge distributions in indolyl(alkoxy)carbenium tetrafluoroborates 2, a new class of highly stabilized carbenium ions, were investigated by 1H and 13C NMR spectroscopy and the crystal structure of indol-3-yl(methoxy)phenylcarbenium tetrafluoroborate (2e) was determined by X-ray diffraction methods. The phenyl-substituted cation of 2e exhibits axial chirality in the crystalline state

scholarly journals Crystal structure of 2-(2,6-diisopropylphenyl)-N,N-diethyl-3,3-dimethyl-2-azaspiro[4.5]decan-1-amine: a diethylamine adduct of a cyclic(alkyl)(amino)carbene (CAAC)

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Roxanne A. Naumann ◽  
Joseph W. Ziller ◽  
Allegra L. Liberman-Martin
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Title Compound ◽  
Lithium Diisopropylamide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compound C ◽  
Lithium Diethylamide ◽  
C Nmr

The structure of the title compound, C27H46N2, at 93 K has monoclinic (P21/n) symmetry. The title compound was prepared by treatment of 2-(2,6-diisopropylbenzene)-3,3-dimethyl-2-azaspiro[4.5]dec-1-en-2-ium hydrogen dichloride with two equivalents of lithium diethylamide. Characterization of the title compound by single-crystal X-ray diffraction and 1H and 13C NMR spectroscopy is presented. Formation of the diethylamine adduct of the cyclic(alkyl)(amino)carbene (CAAC) was unexpected, as deprotonation using lithium diisopropylamide results in free CAAC formation.

Partial Reduction of the N–O Functions of Partially Deprotonated Bis(hydroxylamine) Complexes

2009 ◽  
Vol 64 (10) ◽  
pp. 1208-1212
Author(s):  
Patrick Bösing ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Titanium Tetrachloride ◽  
Partial Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amine Function ◽  
C Nmr

The reduction of a partially deprotonated bishydroxylamine complex {(tBu2Ga)2[cyclo-ON(Me)(CH2)2- (Me)NO][HON(Me)(CH2)2(Me)(H)NO]} with a reagent composed of titanium tetrachloride and methyllithium leads to the reduction of one of the N-O groups to an amine function affording the salt {(tBu2Ga)[cyclo- ON(H)(Me)(CH2)2NHMe]}+ {tBu2GaCl2}−. This has been characterised by 1H and 13C NMR spectroscopy, by elemental analysis and by single crystal X-ray diffraction, showing the neutral amine/hydroxylamine ligand to be present in its tautomeric aminoxide form. The molecules form hexameric cyclic aggregates by N-H···Cl hydrogen bonds.

Phenyl-Induced 3,1,11-Rearrangement in the Synthesis of Mixed Pyrrolyl/Dicarbollide Cobaltadicarbaboranes

1997 ◽  
Vol 62 (8) ◽  
pp. 1263-1272 ◽  
Author(s):  
Josep Bertran ◽  
Clara Viñas ◽  
Sílvia Gomez ◽  
Mouad Lamrani ◽  
Francesc Teixidor ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phenyl Rings ◽  
C Nmr

Mixed pyrrolide cobaltadicarbollides have been prepared from the reaction involving potassium pyrrolide, anhydrous CoCl2 and the [7,8-(C6H5)2-nido-7,8-C2B9H10]- anion in dimethoxyethane. An alternative and higher-yield route consists in the reaction between 1,2-(C6H5)2-closo-1,2-C2B10H10 and potassium pyrrolide in the presence of anhydrous CoCl2. As confirmed by the X-ray diffraction analysis of [3-(η5-NC4H4)-1,11-(C6H5)2-closo-3,1,11-CoC2B9H9], the phenyl rings were found to enhance the rearrangement of the metallacarborane cluster carbons to produce the 3,1,11-isomer instead of the expected 3,1,2-derivative. As suggested by 1H and 13C NMR spectroscopy, the electron-withdrawing properties and steric requirements of the phenyl rings facilitate the rearrangement.

scholarly journals Synthesis and highly efficient light-induced rearrangements of diphenylmethylene(2-benzo[b]thienyl)fulgides and fulgimides

2020 ◽  
Vol 16 ◽  
pp. 1820-1829
Author(s):  
Vladimir P Rybalkin ◽  
Sofiya Yu Zmeeva ◽  
Lidiya L Popova ◽  
Valerii V Tkachev ◽  
Andrey N Utenyshev ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Uv Irradiation ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Efficient ◽  
Shift Reaction ◽  
Photoinduced Rearrangement ◽  
C Nmr

2-Benzo[b]thienyl fulgides and fulgimides containing bulky diphenylmethylene substituents were synthesized in the form of their ring-opened E- or Z-isomers. In contrast to the majority of known fulgides/fulgimides, that form colored ring-closed structures under UV irradiation, the obtained compounds undergo an irreversible transformation leading to decoloration of their solutions. This rearrangement with the formation of the dihydronaphthalene core appeared to be by 2–3 orders of magnitude more efficient than for the known diphenylmethylene(aryl(hetaryl))fulgides. The molecular structures of E- and Z-isomers and of products of the photoinduced rearrangement completed by 1,5-H shift reaction, 3a,4-dihydronaphtho[2,3-c]furans(pyrroles) C, were established based on the data of 1H and 13C NMR spectroscopy and X-ray diffraction studies.

The first example of the stereoselective synthesis and crystal structure of a spirobicycloquinazolinone based on (–)-fenchone and anthranilamide

2019 ◽  
Vol 75 (12) ◽  
pp. 1675-1680 ◽  
Author(s):  
Vladimir V. Chernyshov ◽  
Yuri V. Gatilov ◽  
Olga I. Yarovaya ◽  
Igor P. Koskin ◽  
Spartak S. Yarovoy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Unit Cell Volume ◽  
Stereoselective Synthesis ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
First Time ◽  
C Nmr

The possibility of a single-stage solvent-free stereoselective synthesis of a spirocyclic compound from the natural bicyclic monoterpenoid (−)-fenchone and anthranilamide has been shown for the first time. The molecular and crystal structure of (1R,2S,4S)-1,3,3-trimethyl-1′H-spiro[bicyclo[2.2.1]heptane-2,2′-quinazolin]-4′(3′H)-one, C17H22N2O, was established by X-ray diffraction though the chirality was assumed via the known reactant connectivity and 1H and 13C NMR spectroscopy. It has shown that in the molecule, for steric reasons, there is an elongation of the Me2C—C(N)N bond to 1.603 (5) Å. The formation of dimers via N—H...O=C hydrogen bonds with an interaction energy of 93.30 kJ mol−1 and through cavities (33.7% of the unit-cell volume) was established in the packing of the molecules. There are no π-stacking interactions in the structure.

scholarly journals C–H/N–H Tautomerism of Tetrakis-(2-benzothiazolyl)ethane

1999 ◽  
Vol 23 (7) ◽  
pp. 410-411
Author(s):  
Carla Boga ◽  
Anna Corradi Bonamartini ◽  
Luciano Forlani ◽  
Elisabetta Mezzina ◽  
Andrea Pompa ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Properties ◽  
Title Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
C Nmr

C–H and N–H tautomers of the title compound are obtained and their structural properties determined by 1H and 13C NMR spectroscopy and X-ray diffraction; solvent and base effects on the rate of the C–H to N–H transformation are investigated.

N-alkyl-2-(1,2-diferrocenylvinyl)-4,5-dihydrooxazolinium salts, multi-component synthesis and breaking of their heterocyclic systems

2016 ◽  
Vol 88 (12) ◽  
pp. 1129-1142 ◽  
Author(s):  
Jessica J. Sánchez García ◽  
Marcos Flores-Alamo ◽  
Mark E. Martínez Klimov ◽  
Elena I. Klimova
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkyl Iodides ◽  
New Compounds ◽  
C Nmr

AbstractA new multicomponent method for the synthesis of N-alkyl-2-(Z-1,2-diferrocenylvinyl)-4,5-dihydrooxazolinium salts 3a–f, 5-(N-alkyl-2′,3′-diferrocenyl-acryloylamido)-3-aza-3-alkylpentanols 4a–d, (E)-N-alkyl-N-(2-morpholinoethyl)-2,3-diferrocenylacrylamides 9a,b,e,f and (E)-N-alkyl-N-(2-piperidinoethyl)-2,3-diferrocenylacrylamides 10a,c from reactions of 2,3-diferrocenylcyclopropenone 1 with bis-1,4-N,O-nucleophiles in the presence of triethyloxonium tetrafluoroborate, alkyl iodides, morpholine, piperidine and Et3N is described. The characterization of the new compounds was done by IR, 1H- and 13C-NMR spectroscopy, mass-spectrometry, elemental analysis and X-ray diffraction studies.

Sign in / Sign up

Export Citation Format

Share Document