Synthesis of the six isomeric thieno[c]-fused 1,5- and 1,6-naphthyridines

1991 ◽  
Vol 56 (11) ◽  
pp. 2340-2351 ◽  
Author(s):  
Salo Gronowitz ◽  
Johan Malm ◽  
Anna-Britta Hörnfeldt
Keyword(s):  
Nmr Spectra ◽  
Coupling Reaction ◽  
One Pot ◽  
C Nmr

trough the use of Pd(0)-catalyzed coupling between 2- and 4-formyl-3-thiopheneboronic acids and 3-amino-2-bromopyridine and 4-acetamido-3-bromopyridine, convenient one-pot procedures for the preparation of thieno[2,3-c]-1,5-naphthyridine, thieno[3,4-c]-1,5-naphthyridine, thieno-[2,3-c]-1,6-naphthyridine, and thieno[3,4-c]-1,6-naphthyridine have been developed. In order to obtain thieno[3,2-c]-1,6-naphthyridine 2-(tributylstannyl)-3-thiophene aldehyde had to be used, since the organometallic partner in the coupling reaction, 3-formyl-2-thipheneboronic acid, is too easily deboronated. The effect of silver(I) oxide and thallium(I) carbonate on the coupling was studied. 1H and 13C NMR spectra of the six isomeric thieno{c]-fused 1,5- and 1,6-naphthyridines are discussed.

5-Aminouracil as a Building Block in Heterocyclic Synthesis: Part I. One-pot Synthesis of Pyrimido[5,4-b]quinolin-2,4,9-triones under Microwave Irradiation without Catalyst

2008 ◽  
Vol 63 (12) ◽  
pp. 1431-1437 ◽  
Author(s):  
Raafat M. Shaker ◽  
Mohamed Abd Elrady
Keyword(s):  
Microwave Irradiation ◽  
Potassium Carbonate ◽  
Building Block ◽  
Anhydrous Potassium Carbonate ◽  
Nmr Spectra ◽  
Heterocyclic Synthesis ◽  
One Pot ◽  
One Pot Condensation ◽  
Elemental Analyses ◽  
C Nmr

A series of 6,7,8,10-tetrahydropyrimido[5,4-b]quinolin-2,4,9-(1H,3H,5H)-triones 6 were synthesized through one-pot condensation of 5-aminouracil, aldehydes and dimedone in DMF under microwave irradiation without catalyst. The products 6a, d were oxidized to the 7,8-dihydro-pyrimido- [5,4-b]quinolin-2,4,9-(1H,3H,6H)-triones 11a, b. Treatment of 6a, d and/or 11a, b with ethyl iodide in the presence of anhydrous potassium carbonate gave the ethylated derivatives 12a, b and 13a, b, respectively. The structures of the products were confirmed by elemental analyses, IR, MS, 1H, and 13C NMR spectra.

Synthesis and X-Ray Single Crystal Structure of Dialkyl 2-[1-(2,2-Dimethylpropionyl)-3,3-dimethyl-2-oxobutyl]-3- (triphenylphosphoranylidene)succinates

2006 ◽  
Vol 61 (9) ◽  
pp. 1128-1133 ◽  
Author(s):  
Ali Ramazani ◽  
Ali Reza Kazemizadeh ◽  
Ebrahim Ahmadi ◽  
Katarzyna Ślepokura ◽  
Tadeusz Lis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Nmr Spectra ◽  
Single Crystal Structure ◽  
Phosphorus Ylides ◽  
One Pot ◽  
X Ray ◽  
Dialkyl Acetylenedicarboxylates ◽  
High Yields ◽  
C Nmr

Abstract A one-pot synthesis of sterically congested phosphorus ylides in fairly high yields by the reaction of 2,2,6,6-tetramethyl-3,5-heptanedione, dialkyl acetylenedicarboxylates and triphenylphosphine is reported. The structures of these compounds were confirmed by IR, 1H, 31P and 13C NMR spectroscopy, and X-ray single crystal structure determination. The NMR spectra (CDCl3 as solvent) indicated that the compounds contained two rotamers for each ylide.

Formation of methyl 2-arylhydrazono-3-oxobutanoates and 2-arylhydrazono-3-oxobutanenitriles during the coupling reaction of arenediazonium ions with methyl 3-aminocrotonate and 3-aminocrotononitrile

1995 ◽  
Vol 73 (2) ◽  
pp. 169-175 ◽  
Author(s):  
D. Sean Brown ◽  
Jason V. Jollimore ◽  
Marcus P. Merrin ◽  
Keith Vaughan ◽  
Donald L. Hooper
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Coupling Reaction ◽  
Coupling Reactions ◽  
Diazonium Coupling ◽  
High Yields ◽  
Hydrolysis Of ◽  
C Nmr

Reaction of aryldiazonium salts with methyl 3-aminocrotonate (1) affords high yields of the methyl 2-arylhydrazono-3-oxobutanoates (4); analogous diazonium coupling with 3-aminocrotononitrile (2) gives the 2-arylhydrazono-3-oxobutanenitriles (5). The hydrazones are the product of diazonium coupling at the C2-vinylic carbon, concomitant with hydrolysis of the 3-amino substituent to the 3-oxo derivative; there is no evidence for the formation of a triazene (6), which would be the product of N-coupling. All hydrazones (4a–e and 5a–d) have been fully characterized by IR and 1H and 13C NMR spectroscopy; the NMR spectra of the methyl 2-arylhydrazono-3-oxobutanoates (4) suggest the presence of two isomeric intramolecularly H-bonded forms in solution. Selected compounds were further characterized by elemental analysis and mass spectrometry. A mechanism is proposed for the conversion of 1 or 2 into 4 or 5, and these observations are compared with previously reported observations of diazonium coupling reactions with unsaturated systems. Keywords: hydrazone, diazonium, aminocrotonate, aminocrotononitrile, hydrogen bonding.

Synthesis of Some 2-Aminonitroethanes via Silica Gel-Catalyzed Nitro-Mannich Reaction

2006 ◽  
Vol 61 (9) ◽  
pp. 1162-1165 ◽  
Author(s):  
Ali S. Mahasneh
Keyword(s):  
Silica Gel ◽  
Elemental Analysis ◽  
Mannich Reaction ◽  
Nmr Spectra ◽  
One Pot ◽  
H Nmr ◽  
High Yields ◽  
C Nmr

Abstract A direct one pot, three-component nitro-Mannich reaction of a nonenolizable aldehyde, aniline or one of its ring-substituted derivatives and nitromethane was carried out on silica gel surface. The products of the reaction, 2-aminonitroethane, were obtained in high yields. IR, 1H NMR, 13C NMR spectra and elemental analysis confirmed the structures of the products.

scholarly journals Total Synthesis of (8S) and (8R) Methyl 8-β-d-Glucopyranosyl-Helianthenate B and Their Application for Other Derivatives

2019 ◽  
Vol 14 (7) ◽  
pp. 1934578X1986101
Author(s):  
Rishni Masimbula ◽  
Akiko Yamada ◽  
Kosaku Takahashi ◽  
Hideyuki Matsuura
Keyword(s):  
Total Synthesis ◽  
Nmr Spectra ◽  
Coupling Reaction ◽  
H Nmr ◽  
The Absolute ◽  
C Nmr

The first total synthesis of (8 R) and (8 S) methyl β-d-glucopyranosyl helianthenate B was accomplished using the Cadiot-Chodkiewicz coupling reaction as a key step. Significant differences were observed in the resonances between the 1H-NMR and 13C-NMR spectra of the diastereomers. Based on these results, the absolute configurations of glucopyranosyloxymethine in methyl β-d-glucopyranosyl helianthenate A to E (1 -5) were reconfirmed to be the ( R) configuration.

scholarly journals Complete Assignment ofH1andC13NMR Spectra of 1,2,4-Trisubstituted Pyrroles

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Elsa Anselmi ◽  
Mohamed Abarbri ◽  
Alain Duchêne ◽  
Sandrine Lamandé-Langle ◽  
Jérôme Thibonnet
Keyword(s):  
Carboxylic Acid ◽  
Nmr Spectra ◽  
Cross Coupling ◽  
Ester Group ◽  
Two Dimensional ◽  
Allylic Amination ◽  
One Pot ◽  
Complete Assignment ◽  
New Compounds ◽  
C Nmr

1,2,4-Trisubstituted pyrroles were synthesized with an original one-pot domino allylic amination/palladium-catalysed Sonogashira cross-coupling and heterocyclisation process.1H and13C NMR spectra were assigned for twelve new compounds containing different substituents in positions 1 and 2, and a carboxylic acid or ester group in position 4. Each assignment was based on the combination of one, and two-dimensional experiments (APT, COSY, HMBC).

Conformational structure of ethylene glycol dibenzoate. Vibrational and NMR spectra

1981 ◽  
Vol 46 (8) ◽  
pp. 1913-1929 ◽  
Author(s):  
Bohdan Schneider ◽  
Pavel Sedláček ◽  
Jan Štokr ◽  
Danica Doskočilová ◽  
Jan Lövy
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Conformational Structure ◽  
Infrared And Raman Spectra ◽  
H Nmr ◽  
Liquid States ◽  
Crystalline Forms ◽  
C Nmr

It was found that three crystalline forms of ethylene glycol dibenzoate can be prepared. Infrared and Raman spectra of these three forms, as well as of the glassy and liquid states, were measured. From 3JHH coupling constants obtained by analysis of the 13C satellite band of the -CH2- group in 1H NMR spectra, and from the 3JCH coupling constants of the -CO.O.CH2- fragment obtained by analysis of the carbonyl band in 13C NMR spectra it was found that in the liquid state the -CH2-CH2- group exists predominantly in the gauche conformational structure, and the bonds C-O-C-C assume predominantly a trans orientation. The results of the analysis of NMR and vibrational spectra were used for the structural interpretation of conformationally sensitive bands in vibrational spectra of ethylene glycol dibenzoate.

13C NMR spectra of 1-aryl-ferrocenylethylenes

1986 ◽  
Vol 51 (3) ◽  
pp. 670-676 ◽  
Author(s):  
Eva Solčániová ◽  
Štefan Toma ◽  
Tibor Liptaj
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Substituent Effects ◽  
13C Nmr Spectra ◽  
Bridge Group ◽  
C Nmr ◽  
Electron Effects

13C NMR spectra of 18 ferrocene analogues of trans stilbenes (1-aryl-2-ferrocenylethylenes) were measured. It was found that bridge group weakens the transfer of the substituent electron effects into ferrocene nucleus, especially distinctly into 3',4'positions of cyclopentadienyl ring. The transfer of substituent effects into β-position of the bridge -CH=CH- is greater in derivatives studied by us than in stilbenes. Synthesis of 1-(4-dimethylaminophenyl)-2-ferrocenylethylene is described.

The synthesis and stereochemistry of the ternary cobalt(III) complex with a stereospecific ligand derived from (S)-leucine

1986 ◽  
Vol 51 (2) ◽  
pp. 318-326 ◽  
Author(s):  
Milan Strašák ◽  
Pavol Novomeský
Keyword(s):  
Ir Spectroscopy ◽  
Aqueous Medium ◽  
Absorption Spectroscopy ◽  
Absolute Configuration ◽  
Nmr Spectra ◽  
Methyl Groups ◽  
Electron Absorption Spectroscopy ◽  
Electron Absorption ◽  
C Nmr

A new stereospecific ligand, ethylenediamine-N,N'-di(S)-α-isocapronic acid, was synthesized by condensation of (S)-leucine with 1,2-dibromoethane in alkaline aqueous medium. It follows from the 1H and 13C NMR spectra that the terminal methyl groups are chemically and magnetically nonequivalent. Of the four theoretically possible isomers of the ternary cobalt (III) complex with ethylenediamine, separation on catex yielded only one, whose absolute configuration was determined by a combination of 1H and 13C NMR, electron absorption spectroscopy and CD and IR spectroscopy.

17O and 13C NMR spectra of some geminal diacetates

1988 ◽  
Vol 53 (3) ◽  
pp. 588-592 ◽  
Author(s):  
Antonín Lyčka ◽  
Josef Jirman ◽  
Jaroslav Holeček
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
The Other ◽  
13C Nmr Spectra ◽  
Other Hand ◽  
Carboxylic Esters ◽  
C Nmr ◽  
Oxygen Atoms

The 17O and 13C NMR spectra of eight geminal diacetates RCH(O(CO)CH3)2 derived from simple aldehydes have been measured. In contrast to the dicarboxylates R1R2E(O(CO)R3)2, where E = Si, Ge, or Sn, whose 17O NMR spectra only contain a single signal, and, on the other hand, in accordance with organic carboxylic esters, the 17O NMR spectra of the compound group studied always exhibit two well-resolved signals with the chemical shifts δ(17O) in the regions of 183-219 ppm and 369-381 ppm for the oxygen atoms in the groups C-O and C=O, respectively.

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