A simple synthesis of benzimidazole N-oxides from 2-nitroaniline derivatives — Scope and limitations

2004 ◽  
Vol 82 (8) ◽  
pp. 1322-1327 ◽  
Author(s):  
Elba I Buján ◽  
María Laura Salum
Keyword(s):  
Aromatic Ring ◽  
Good Yield ◽  
Simple Synthesis ◽  
Amino Group ◽  
Effect Of Substituents

Several benzimidazole N-oxide derivatives were synthesized in very good yield by heating at reflux the corresponding N-alkyl-2-nitroaniline derivative with NaOH in 60% 1,4-dioxane–water. The effect of substituents on the aromatic ring and amino group on the reaction is discussed.Key words: synthesis, benzimidazole N-oxides.

Effect of substituents on absorption and fluorescence properties of pyrazolo[3,4-b]pyrrolo[2,3-d]pyridines

2008 ◽  
Vol 86 (11) ◽  
pp. 1070-1076 ◽  
Author(s):  
Bhausaheb K Ghotekar ◽  
Muddassar A Kazi ◽  
Madhukar N Jachak ◽  
Raghunath B Toche
Keyword(s):  
Good Yield ◽  
Substituent Effect ◽  
Photophysical Properties ◽  
Fluorescence Properties ◽  
Absorption And Emission ◽  
Effect Of Substituents ◽  
Convenient Route

A convenient route was successfully developed for the synthesis of novel heterocycles such as pyrazolo[3,4-b]pyrrolo[2,3-d]pyridines (PPP) from pyrazolo[3,4-b]pyridines in good yield. The PPP derivatives synthesized were further studied for their photophysical properties, and it was observed that absorption and emission λmax changed, owing to the substituent effect at 4 positions. These compounds were obtained from highly reactive starting materials, 5-aminopyrazoles and α-acetyl γ-butyrolactone.Key words: α-acetyl γ-butyrolactone, pyrazolo[3,4-b]pyrrolo[2,3-d] pyridine, absorption, emission, fluorescence.

A Simple Synthesis of 4-Substituted 2-(3-Hydroxy-2-oxo-1-phenethylpropylcarbamoyl) pyrrolidine-1-carboxylic Acid Benzyl Esters as Novel Cysteine Protease Inhibitors

2008 ◽  
Vol 63 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Seikwan Oh ◽  
Jae-Chul Jung ◽  
Mitchell A. Avery
Keyword(s):  
Carboxylic Acid ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Good Yield ◽  
Sodium Acetate ◽  
Simple Synthesis ◽  
Insertion Reaction ◽  
Cysteine Protease Inhibitors ◽  
Convenient Synthesis ◽  
Benzyl Esters

A convenient synthesis of 4-substituted 2-(3-hydroxy-2-oxo-1-phenethylpropylcarbamoyl)pyrrolidine- 1-carboxylic acid benzyl esters 17 and 18 as new cysteine protease inhibitors is described. The synthetic key strategies involve the diazocarbonyl insertion reaction of N-Boc-L-homophenylalanine (1) by diazomethane, acetylation of the bromoketone 2 with sodium acetate, and condensation of acids 12, 14 with (3S)-3-amino-2-oxo-5-phenyl-pentyl acetate monohydrochloride (4) in good yield

Effect of Substituents on the Chemical Shift of Benzylic Protons. III

1971 ◽  
Vol 49 (5) ◽  
pp. 800-802 ◽  
Author(s):  
Robert R. Fraser ◽  
Roger N. Renaud
Keyword(s):  
Chemical Shift ◽  
Aromatic Ring ◽  
Chemical Shifts ◽  
Dominant Factor ◽  
Chiral Molecules ◽  
Effect Of Substituents ◽  
Number Of Factors

The effects of para substituents on the chemical shifts of the diastereotopic benzylic protons in three series of chiral molecules have been determined from a study of the 100 MHz spectra of these molecules in deuterochloroform. The results show that the slope, ρ, obtained from a plot of τ vs. Hammett σ constant, is influenced by a number of factors and that the conformational disposition of the benzylic proton with respect to the aromatic ring is not a dominant factor.

scholarly journals A Cascade Suzuki–Miyaura/Diels–Alder Protocol: Exploring the Bifunctional Utility of Vinyl Bpin

Synlett ◽  
2018 ◽  
Vol 30 (07) ◽  
pp. 787-791 ◽  
Author(s):  
David Cain ◽  
Calum McLaughlin ◽  
John Molloy ◽  
Cameron Carpenter-Warren ◽  
Niall Anderson ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Good Yield ◽  
Cross Coupling ◽  
Cascade Reactions ◽  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction

Cascade reactions are an important strategy in reaction ­design, allowing streamlining of chemical synthesis. Here we report a cascade Suzuki–Miyaura/Diels–Alder reaction, employing vinyl Bpin as a bifunctional reagent in two distinct roles: as an organoboron nucleo­phile for cross-coupling and as a Diels–Alder dienophile. Merging these two reactions enables a rapid and operationally simple synthesis of functionalized carbocycles in good yield. The effect of the organoboron subtype on Diels–Alder regioselectivity was investigated and postsynthetic modifications were carried out on a model substrate. The potential for a complementary Heck/Diels–Alder process was also assessed.

Sign in / Sign up

Export Citation Format

Share Document