Structure and Properties of Quaternized 2- and 4-Aminonicotinamides

1995 ◽  
Vol 60 (6) ◽  
pp. 1009-1015
Author(s):  
Svatava Smrčková-Voltrová ◽  
Jaroslav Říha ◽  
Viktor Prutianov
Keyword(s):  
Benzene Ring ◽  
Spectral Properties ◽  
Nmr Spectra ◽  
Electronic Effect ◽  
Structure And Properties ◽  
Reaction Conditions ◽  
Iminium Salts ◽  
Substituted 1 ◽  
Optimal Reaction ◽  
C Nmr

Compounds 2- and 4-aminonicotinamide were quaternized with eight 4-substituted 1-bromomethylbenzenes to form 1-(4-substituted benzyl)-3-carbamoyl-1,2(1,4)-dihydropyridin-2(4)-iminium bromides. The optimal reaction conditions were found and the resulting iminium salts were characterized by 1H and 13C NMR spectra. No transmission of electronic effect of the substituent at the benzene ring on the spectral properties of dihydropyridine moiety was observed. The possible reason is discussed.

Proximity and conformation effects in 29Si and 13C NMR spectra of di-ortho substituted trimethylsiloxybenzenes

1990 ◽  
Vol 55 (8) ◽  
pp. 2027-2032 ◽  
Author(s):  
Jan Schraml ◽  
Robert Brežný ◽  
Jan Čermák
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Proximity Effect ◽  
Nmr Spectra ◽  
Methoxy Group ◽  
Chemical Shifts ◽  
Proximity Effects ◽  
13C Nmr Spectra ◽  
Methoxy Groups ◽  
C Nmr

29Si and 13C NMR spectra of five 4-substituted 2,6-dimethoxytrimethylsiloxybenzenes were studied with the aim to elucidate the nature of the deshielding proximity effects observed in the spectra of ortho substituted trimethylsiloxybenzenes. The sensitivity of 29Si chemical shifts to para substitution is in the studied compounds essentially the same as in mono ortho methoxytrimethylsiloxybenzenes. The deshielding proximity effect of the ìsecondî methoxy group is somewhat smaller than that of the ìfirstî group. The present results indicate that the two methoxy groups assume coplanar conformations with the benzene ring and are turned away from the trimethylsiloxy group which is not in the benzene plane. It is argued that in mono ortho methoxytrimethylsiloxybenzenes the two substituent groups adopt the same conformations as in the compounds studied here.

Nuclear Magnetic Resonance Studies on Aromatic Compounds, IV 13C NMR Spectra of Some Disulpho-substituted 1- and 2-Naphthols

1977 ◽  
Vol 32 (7) ◽  
pp. 818-820 ◽  
Author(s):  
Kauko Räisänen ◽  
Lauri H. J. Lajunen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Aromatic Compounds ◽  
Nmr Spectra ◽  
Hydroxyl Group ◽  
Mesomeric Effect ◽  
13C Nmr Spectra ◽  
Magnetic Resonance Studies ◽  
Fine Splitting ◽  
Substituted 1 ◽  
C Nmr

The 13C NMR spectra of 1-hydroxynaphthalene-3,6-disulphonic, 1-hydroxynaphthalene- 3,8-disulphonic, 2-hydroxynaphthalene-3,6-disulphonic, and 2-hydroxynaphthalene-6,8-disulphonic acids were determined with and without noise-decoupling. The fine splitting caused by the long-range couplings pattern was used in the identification of the resonances lines of the 13C nuclei. The combined influence of the mesomeric effect of the hydroxyl group and that of the sulphonate groups have been discussed.

Reaction of 30-nor-19(20)-lupene derivatives with bromine

1983 ◽  
Vol 48 (12) ◽  
pp. 3444-3454 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Jiří Protiva ◽  
Jiří Urban ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
Hydroxy Ketone ◽  
Reaction Conditions ◽  
Unsaturated Alcohols ◽  
C Nmr ◽  
Dibromo Derivative

The reaction of 30-nor-19-lupene-3β,28-diol (I) with bromine gives bromo ether III; from the corresponding diacetate II diene IX, unsaturated alcohols VII and VIII and hydroxy ketone XIV were obtained as products of conversion of the primarily formed dibromo derivative VI, depending on the reaction conditions. The structure and configuration of unsaturated alcohols VII and VIII at C(20) is based on 1H and 13C NMR spectra and the different course of their reaction with peracid.

Increments for 1H and 13C NMR chemical shifts in pinacol arylboronates

2012 ◽  
Vol 90 (1) ◽  
pp. 71-74
Author(s):  
Di Qiu ◽  
Zhitong Zheng ◽  
Fanyang Mo ◽  
Yan Zhang ◽  
Jianbo Wang
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Cross Coupling Reactions ◽  
C Nmr

Arylboronates are important compounds widely used in cross-coupling reactions. By analyzing the NMR spectra data of a variety of pinacol arylboronates, we have determined the increments for 1H and 13C NMR chemical shifts caused by a pinacol boronate substituent in the benzene ring. These data can be used in the estimation of chemical shifts of aromatic pinacol boronates.

scholarly journals Substituent and Solvent Polarity on the Spectroscopic Properties in Azo Derivatives of 2-Hydroxynaphthalene and Their Difluoroboranes Complexes

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3387
Author(s):  
Agnieszka Skotnicka ◽  
Przemysław Czeleń
Keyword(s):  
Spectral Properties ◽  
Nmr Spectra ◽  
Fluorescent Dyes ◽  
Photophysical Properties ◽  
Solvent Polarity ◽  
Spectroscopic Properties ◽  
Azo Group ◽  
Group Rotation ◽  
Derivatives Of ◽  
Substituted 1

Novel fluorescent dyes such as difluoroborane complexes of 1-phenylazonaphthalen-2-ol derivatives were successfully synthesized and characterized with a focus on the influence of a substituent and a solvent on the basic photophysical properties. 1H, 11B, 13C, 15N, and 19F nuclear magnetic resonance (NMR) spectra of substituted 1-phenylazonaphthalen-2-ol difluoroboranes and their parent azo dyes were recorded and discussed. The absorption and emission properties of synthesized compounds were investigated in solvents of varying polarity. They were found to be fluorescent despite the presence of the azo group. The azo group rotation was blocked by complexing with -BF2 to get a red shift in absorption. Solvent-dependent spectral properties of compounds were investigated using Lipper-Mataga and Bakhshiev plot. The calculated DFT energies and Frontier Molecular Orbitals calculations of the studied compounds were proved to be consistent with the experimental observations.

scholarly journals Boric Acid Catalyzed Convenient Synthesis of Benzimidazoles in Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Reza Poor Heravi ◽  
Marjan Ashori
Keyword(s):  
Boric Acid ◽  
Nmr Spectra ◽  
Aqueous Media ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
H Nmr ◽  
Convenient Synthesis ◽  
Ft Ir ◽  
Acid Catalyzed ◽  
C Nmr

Synthesis of benzimidazoles has been developed by theo-phenylenediamine with aldehydes using boric acid an efficient catalyst under mild reaction conditions in aqueous media. The product is applicable to aryl and heteroaryl aldehydes. This reaction led to the formation of benzimidazoles new derivatives in good yields. The FT-IR,19F-NMR,1H-NMR,13C-NMR spectra and elemental analysis confirm the structure of compounds.

13C NMR study of 3-(X-benzal)phthalides and 2-(X-benzal)-1,3-indanediones

1980 ◽  
Vol 45 (10) ◽  
pp. 2772-2778 ◽  
Author(s):  
Eva Solčániová ◽  
Pavol Hrnčiar ◽  
Tibor Liptaj
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Electronic Effect ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Carbonyl Groups ◽  
Aryl Group ◽  
Nmr Study ◽  
Derivatives Of ◽  
C Nmr

13C NMR spectra of 14 derivatives of 3-(X-benzal)phthalides (I) and 10 derivatives of 2-(X-benzal)-1,3-indanediones (II) were investigated. The correlation of 13C chemical shifts of carbon atoms of the phthalide ring with σ-constants showed that the electronic effect of substituents was transmitted from the benzylidene group of 3-(X-benzal)phthalides on the chemical shift of the carbonyl group not only through oxygen, but also through the aromatic ring of the phthalide moiety. The transmission of substituent effects in 2-(X-benzal)-1,3-indanediones on the chemical shift of the carbonyl groups was more pronounced on the carbonyl, which is in the trans-arrangement with respect to the aryl group. This phenomenon was also observed at carbon atoms of the benzene ring of the indanedione moiety closer to the trans-CO group.

Synthesis and NMR Studies of Some Steroidal Isoxazoles

1992 ◽  
Vol 47 (6) ◽  
pp. 891-897 ◽  
Author(s):  
Sergio Giacopello ◽  
Mónica E. Deluca ◽  
Alicia M. Seldes
Keyword(s):  
Nmr Spectra ◽  
Two Dimensional ◽  
Model Compounds ◽  
Nmr Studies ◽  
Reaction Conditions ◽  
Related Model ◽  
H Nmr ◽  
Short Synthesis ◽  
Nmr Methods ◽  
C Nmr

A short synthesis of 17α-pregna-2,4-dien-[2,3-d]isoxazol-17β-ol (1) is described using mild reaction conditions and with a high overall yield. The equilibrium between keto-enolic forms has been studied by 1H NMR methods. Complete assignments of all the resonances in the 1H and 13C NMR spectra of Danazol have been made using a variety of one and two-dimensional correlation methods. 13C NMR spectra of all the intermediate and related model compounds were also assigned.

Reaction Pathways and the Role of Solvent in the Hydrogenation of Chloronitrobenzenes

2003 ◽  
Vol 68 (10) ◽  
pp. 1819-1832 ◽  
Author(s):  
Vieroslav Krátky ◽  
Milan Králik ◽  
Alexander Kaszonyi ◽  
Magdaléna Stolcová ◽  
Lubomír Zalibera ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Benzene Ring ◽  
Catalyst Activity ◽  
Reaction Pathways ◽  
Reaction Conditions ◽  
Liquid Phase Hydrogenation ◽  
Role Of Solvent ◽  
Hplc Analyses ◽  
C Nmr

Liquid phase hydrogenation of chloronitrobenzenes to corresponding chloroanilines over Pd on carbon (Pd/C) under mild reaction conditions was studied. On the basis of 1H, 13C NMR, GC-MS and HPLC analyses of reaction mixtures, the reaction pathways were evaluated. The reduction of substrates proceeds via the formation of chloronitrosobenzenes and N-(chlorophenyl)hydroxylamines and mainly results in the formation of the chloroanilines and aniline. Aniline is formed by hydrogenolysis of chlorine (dechlorination) in benzene ring. Other compounds (mono- and disubstituted azobenzenes and azoxybenzenes) were also detected by GS-MS and HPLC (<3 mole %). The used solvent influences the reaction mixture composition and catalyst activity.

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