Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 

Saved Queries

Sign in to use this feature.

Search Filter Reset All

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Subjects Reset
Select Subjects

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Journals Reset
Select Journals

Article Types

remove_circle_outline
remove_circle_outline
Add Article Types Reset
Select Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Countries / Regions Reset
Select Countries / Regions
Update Search
share announcement

Search Results (4)

Search Parameters:
Keywords = β-ketonitrile

Order results
Result details
Results per page
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
6 pages, 1256 KiB  
Communication
Synthesis and Intramolecular Regioselective Cyclization of 2-Cyano-3,10-dioxo-1,10-seco-1,25-dinorlupan-28-yl Benzoate
by Irina Tolmacheva, Mikhail Nazarov and Victoria Grishko
Molbank 2025, 2025(2), M1990; https://doi.org/10.3390/M1990 - 7 Apr 2025
Viewed by 585
Abstract
The paper describes the synthesis of a new 1,10-seco-triterpenoid with a 2-cyano-3,10-diketone fragment and its further regioselective cyclization under acidic and basic conditions with the formation of 2S-cyanopyran-3-one derivative or A-pentacyclic alkene β-ketonitrile, respectively. Full article
(This article belongs to the Section Natural Product Chemistry)
►▼ Show Figures

Figure 1

9 pages, 2049 KiB  
Article
Three-Component Condensation of β-Ketonitriles, 4-Fluorobenzaldehyde, and Secondary Cyclic Amines
by Dmitry V. Osipov, Kirill S. Korzhenko and Vitaly A. Osyanin
Reactions 2022, 3(4), 625-633; https://doi.org/10.3390/reactions3040042 - 12 Dec 2022
Cited by 1 | Viewed by 3896
Abstract
A new three-component condensation of β-ketonitriles, 4-fluorobenzaldehyde, and secondary cyclic amines was developed. A possible reaction mechanism has been proposed including Knoevenagel condensation followed by aromatic nucleophilic substitution. It was found that in the case of 3-oxopropanenitrile bearing the 6-amino-1,3-dimethyluracil moiety, the reaction [...] Read more.
A new three-component condensation of β-ketonitriles, 4-fluorobenzaldehyde, and secondary cyclic amines was developed. A possible reaction mechanism has been proposed including Knoevenagel condensation followed by aromatic nucleophilic substitution. It was found that in the case of 3-oxopropanenitrile bearing the 6-amino-1,3-dimethyluracil moiety, the reaction is not accompanied by fluorine substitution in the Knoevenagel adduct, and the Michael addition of a secondary amine occurs followed by oxidation. Full article
►▼ Show Figures

Figure 1

19 pages, 14201 KiB  
Article
Domino Nitro Reduction-Friedländer Heterocyclization for the Preparation of Quinolines
by Kwabena Fobi and Richard A. Bunce
Molecules 2022, 27(13), 4123; https://doi.org/10.3390/molecules27134123 - 27 Jun 2022
Cited by 4 | Viewed by 2883
Abstract
The Friedländer synthesis offers efficient access to substituted quinolines from 2-aminobenzaldehydes and activated ketones in the presence of a base. The disadvantage of this procedure lies in the fact that relatively few 2-aminobenzaldehyde derivatives are readily available. To overcome this problem, we report [...] Read more.
The Friedländer synthesis offers efficient access to substituted quinolines from 2-aminobenzaldehydes and activated ketones in the presence of a base. The disadvantage of this procedure lies in the fact that relatively few 2-aminobenzaldehyde derivatives are readily available. To overcome this problem, we report a modification of this process involving the in situ reduction of 2-nitrobenzaldehydes with Fe/AcOH in the presence of active methylene compounds (AMCs) to produce substituted quinolines in high yields. The conditions are mild enough to tolerate a wide range of functionality in both reacting partners and promote reactions not only with phenyl and benzyl ketones, but also with β-keto-esters, β-keto-nitriles, β-keto-sulfones and β-diketones. The reaction of 2-nitroaromatic ketones with unsymmetrical AMCs is less reliable, giving a competitive formation of substituted quinolin-2(1H)-ones from the cyclization of the Z Knoevenagel intermediate which appears to be favored when certain large groups are adjacent to the AMC ketone carbonyl. Full article
(This article belongs to the Special Issue Heterocycles: Synthesis, Biological Activity and Synthetic Applications)
►▼ Show Figures

Graphical abstract

13 pages, 1113 KiB  
Article
Microwave-Assisted Synthesis, Proton Dissociation Processes, and Anticancer Evaluation of Novel D-Ring-Fused Steroidal 5-Amino-1-Arylpyrazoles
by Gergő Mótyán, Ádám Baji, Małgorzata Anna Marć, Mohana Krishna Gopisetty, Dóra I. Adamecz, Mónika Kiricsi, Éva A. Enyedy and Éva Frank
Appl. Sci. 2020, 10(1), 229; https://doi.org/10.3390/app10010229 - 27 Dec 2019
Cited by 7 | Viewed by 3148
Abstract
Taking into account the pharmacological relevance of heterocycle-fused natural steroids, the objective of the current study was to develop a multistep reaction sequence for the efficient synthesis of novel D-ring-condensed 5-amino-1-arylpyrazoles from dehydroepiandrosterone (DHEA). A condensation reaction of 16-formyl-DHEA with hydroxylamine afforded the [...] Read more.
Taking into account the pharmacological relevance of heterocycle-fused natural steroids, the objective of the current study was to develop a multistep reaction sequence for the efficient synthesis of novel D-ring-condensed 5-amino-1-arylpyrazoles from dehydroepiandrosterone (DHEA). A condensation reaction of 16-formyl-DHEA with hydroxylamine afforded the corresponding oxime, which was demonstrated to be stable in one of its cyclic isoxazoline forms due to possible ring-chain tautomerism. The subsequent base-induced dehydration to a diastereomeric β-ketonitrile, followed by microwave-assisted heterocyclization with different arylhydrazines led to the desired pyrazoles. The generally good yields of the products depended slightly on the electronic character of the substituent present on the aromatic ring of the reagent. The proton dissociation processes of the DHEA-derived heterocycles were investigated in aqueous solution by UV-visible spectrophotometric titrations to reveal their actual chemical forms at physiological pH. The determined pKa values attributed to the pyrazole NH+ moiety were low (1.8–4.0) and varied by the different substituents of the benzene ring. The antiproliferative effects of the structurally similar compounds were screened in vitro on human cancer cells (namely on HeLa, U2Os, MCF-7, PC-3, and A549), along with a noncancerous cell line (MRC-5). The IC50 values of the most active derivative were determined on all cell lines. Full article
(This article belongs to the Special Issue Design, Synthesis and Biological Evaluation of N-Heterocyclic Derivatives and Related Compounds)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying article 1-50 on page 1 of 1.
Back to TopTop