scholarly journals Synthesis, Reactivity and Stability of Aryl Halide Protecting Groups towards Di-Substituted Pyridines

2018 ◽  
Vol 16 (1) ◽  
pp. 53
Author(s):  
Ptoton Mnangat Brian ◽  
Peter Musau
Keyword(s):  
Nitrogen Atom ◽  
Pyridine Ring ◽  
Aryl Halide ◽  
Protecting Groups ◽  
Pyridinium Salts ◽  
Substituted Pyridines ◽  
Benzyl Halides

This paper reports the synthesis and reactivity of different Benzyl derivative protecting groups. The synthesis and stability of Benzyl halides, 4-methoxybenzyl halides, 3,5-dimethoxybenzyl halides, 3,4-dimethoxybenzyl halides, 3,4,5-trimethoxybenzyl halide protecting groups and their reactivity towards nitrogen atom of a di-substituted pyridine ring in formation of pyridinium salts is also reported.

Oxidation of polysubstituted pyridinium salts

1982 ◽  
Vol 47 (5) ◽  
pp. 1494-1502 ◽  
Author(s):  
Petr Nesvadba ◽  
Josef Kuthan
Keyword(s):  
Alkaline Medium ◽  
Electrophilic Substitution ◽  
Pyridine Ring ◽  
Potassium Ferricyanide ◽  
Pyridinium Salts ◽  
Complex Reaction

Oxidation of 1-substituted 2,4,6-triphenylpyridinium salts Ia-Ij with potassium ferricyanide in an alkaline medium was accompanied by contraction of the pyridine ring and formation of 1,2,3,5-tetrasubstituted pyrroles II. The derivative IIf underwent facile electrophilic substitution in the position 4. Contrary to compounds Ia-Ij, the 1-substituted-2,6-diphenylpyridinium salts IIIa,b were oxidized to give a complex reaction mixture containing 4-pyridones IVa,b.

Synthesis of Alkoxy-Substituted Pyridines from Mono- and Tricationic Pyridinium Salts

Synthesis ◽  
2005 ◽  
Vol 2005 (05) ◽  
pp. 781-786 ◽  
Author(s):  
Andreas Schmidt ◽  
Thorsten Mordhorst
Keyword(s):  
Pyridinium Salts ◽  
Substituted Pyridines

Base-catalyzed rearrangement of N-(aryloxy)pyridinium salts. Effect of a 3-substituent in the pyridine ring upon orientation. Synthesis of novel tricyclic rings

1983 ◽  
Vol 48 (5) ◽  
pp. 690-695 ◽  
Author(s):  
Rudolph A. Abramovitch ◽  
Muthiah N. Inbasekaran ◽  
Shozo Kato ◽  
Teresa A. Radzikowska ◽  
Piotr Tomasik
Keyword(s):  
Pyridine Ring ◽  
Pyridinium Salts ◽  
Tricyclic Rings

A general synthesis of 5,7-diaminoimidazo[4,5-b]pyridine ribosides ("2-amino-1-deazaadenosines") from 5-amino-4-imidazolecarboxamide riboside (AICA riboside)

1992 ◽  
Vol 70 (5) ◽  
pp. 1288-1295 ◽  
Author(s):  
John E. Francis ◽  
Michael A. Moskal
Keyword(s):  
Pyridine Ring ◽  
Sodium Hydride ◽  
Ring System ◽  
Ring Closure ◽  
Protecting Groups ◽  
Amino Group ◽  
Phosphoryl Chloride ◽  
Compound A ◽  
General Synthesis ◽  
Methyl Analog

A short general synthesis of 5-substituted 5,7-diaminoimidazo[4,5-b]pyridines from 5-amino-4-imidazolecarboxamide riboside (AICA riboside) was designed to prepare isosteres of substituted 2-aminoadenosines that are selective adenosine A2 receptor agonists. AICA riboside was converted to a hydroxyl-protected 5-amino-4-imidazolecarbonitrile riboside and reacted with an N,N-disubstituted acetamide in the presence of phosphoryl chloride. Sodium hydride treatment completed the ring closure and introduced the 7-amino group. The hydroxyl protecting groups were removed under standard conditions. N-Substitution of the acetamide by one benzyl moiety led to a 5-N-substituted derivative through hydrogenolysis whereas N,N-dibenzylacetamide led to the 5,7-diamino compound. A 6-methyl analog was obtained from an N,N-disubstituted propionamide. This synthesis may be adapted to other heterocyclic systems, as illustrated by the preparation of an example of the imidazo[4,5-b]pyrrolo[3,2-e]pyridine ring system.

Synthesis of 6-aminohexyl esters of uridine nucleotides

1979 ◽  
Vol 44 (2) ◽  
pp. 589-592 ◽  
Author(s):  
Jiří Smrt
Keyword(s):  
Protecting Groups ◽  
Pyridinium Salts ◽  
Uridine Nucleotides

6-Aminohexyl esters of uridine 3'-phosphate (V) and uridine 5'-phosphate (VI) were prepared by condensation of 6-trifluoroacetamidohexanol (IV) with pyridinium salts of the protected corresponding phosphates by means of N,N'-dicyclohexylcarbodiimide followed by removal of protecting groups.

13C-NMR Quanternisation Shift Increments for 3-Substituted Pyridines in N-Banzyl- and N-2,4-Dinitrophenyl-pyridinium Salts

Heterocycles ◽  
1983 ◽  
Vol 20 (2) ◽  
pp. 239 ◽  
Author(s):  
Roger A. Dommisse ◽  
Roger Dommisse ◽  
Eddy Freyne ◽  
Josef Lepoivre ◽  
Frank Alderweireldt
Keyword(s):  
13C Nmr ◽  
Pyridinium Salts ◽  
Substituted Pyridines
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