Synthesis and Anticonvulsant Activity of 5-Phenyl-[1,2,4]-triazolo[4,3-a]quinolines

Access to quinolinones via DMAP-catalysed cascade reaction of 2-substituted benzoic acids with organic azides

Herein, we report a DMAP-catalysed Curtius rearrangement and intramolecular cyclisation cascade reaction of 2-substituted aryl carboxylic acids with organic azides for the first time. This protocol features simple operation, broad scope and metal-free conditions, furnishing a broad spectrum of biologically attractive heterocycles. The synthetic virtue of this reaction was demonstrated by gram-scale synthesis and applicability toward drug-like molecules.

Electrophilically Activated Nitroalkanes in Double Annulation of [1,2,4]Triazolo[4,3-a]quinolines and 1,3,4-Oxadiazole Rings

Nitroalkanes activated with polyphosphoric acid could serve as efficient electrophiles in reactions with amines and hydrazines, enabling various cascade transformations toward heterocyclic systems. This strategy was developed for an innovative synthetic protocol employing simultaneous or sequential annulation of two different heterocyclic cores, affording [1,2,4]triazolo[4,3-a]quinolines with 1,3,4-oxadiazole substituents.

Synthesis of Green/Blue Light Emitting Quinolines by Aza-D-A Reaction Using InCl3 Catalyst

An efficient InCl3-catalyzed sequential reaction of aromatic amines, aromatic aldehydes and functionalized alkynes leading to the formation of new quinoline derivatives exhibiting significant fluorescence activities is described. The photophysical investigations of quinolines were carried out by absorption and photoluminescence measurements. One particular compound 4 h having maximum intensity, emitting green colour (Φ = 0.78) with average life time of 6.20 ns was the best amongst the tested compounds. The presence of the amino group at the 4-aryl substituent of the quinoline backbone played an important role in executing the Povarov cyclization successfully and enhancing the flourescence properties of the newly synthesized quinolines.

Hetero-bimetallic cooperative catalysis for the synthesis of heteroarenes

Review covering the synthesis of 5- and 6-membered as well as condensed heteroarenes, focussing on the combinations in cooperative catalytic systems in strategies used to achieve selectivity and also highlights the mode of action for the cooperative catalysis leading to the synthesis of commercially and biologically relevant heteroarenes.

Recent developments on triazole nucleus in anticonvulsant compounds: a review

Epilepsy is one of the common diseases seriously threatening life and health of human. More than 50 million people are suffering from this condition and anticonvulsant agents are the main treatment. However, side effects and intolerance, and a lack of efficacy limit the application of the current anticonvulsant agents. The search for new anticonvulsant agents with higher efficacy and lower toxicity continues to be the focus and task in medicinal chemistry. Numbers of triazole derivatives as clinical drugs or candidates have been frequently employed for the treatment of various types of diseases, which have proved the importance of this heterocyclic nucleus in drug design and discovery. Recently many endeavours were made to involve the triazole into the anticonvulsants design, which have brought lots of active compounds. This work is an attempt to systematically review the research of triazole derivatives in the design and development of anticonvulsant agents during the past two decades.

Synthesis of substituted 4-hydroxyalkyl-quinoline derivatives by a three-component reaction using CuCl/AuCl as sequential catalysts

A new method to construct 4-hydroxyalkyl-quinoline derivatives is described via Cu(i) and Au(i) sequential catalyzed cyclization of anilines with aldehyde derivatives and aliphatic alkynes, respectively.

Synthesis, crystallographic characterization, molecular docking and biological activity of isoquinoline derivatives

The main objective of this work was to synthesize novel compounds with a benzo[de][1,2,4]triazolo[5,1-a]isoquinoline scaffold by employing (dioxo-benzo[de]isoquinolin-2-yl) thiourea as a building block. Molecular docking was conducted in the COX-2 active site to predict the plausible binding mode and rationalize the structure–activity relationship of the synthesized compounds. The structures of the synthesized compounds were confirmed by HREI-MS, and NMR spectra along with X-ray diffraction were collected for products 1 and 5. Thereafter, anti-inflammatory effect of molecules 1–20 was evaluated in vivo using carrageenan-induced paw edema method, revealing significant inhibition potency in albino rats with an activity comparable to that of the standard drugs indomethacin. Compounds 8, 9, 15 and 16 showed the highest anti-inflammatory activity. However, thermal sensitivity-hot plat test, a radiological examination and motor coordination assessment were performed to test the activity against rheumatoid arthritis. The obtained results indicate promising anti-arthritic activity for compounds 9 and 15 as significant reduction of the serum level of interleukin-1β [IL-1β], cyclooxygenase-2 [COX-2] and prostaglandin E2 [PGE2] was observed in CFA rats.

The importance of triazole scaffold in the development of anticonvulsant agents

Epilepsy is one of the most important neurological disorders with high prevalence worldwide. Many epileptic patients are not completely treated with available drugs and need multiple therapies. Also, many antiepileptic drugs have shown unwanted side effects and drug interactions. Therefore there are continuing interests to find new anticonvulsant drugs. Triazole ring has been found in the structure of many compounds with diverse biological effects. Due to the success of several triazole-containing drugs that entered the pharmaceutical market as CNS-active drugs, this class of heterocyclic compounds has great importance for discovery and development of new anticonvulsant drugs. In this article, we have tried to summarize the latest efforts which have been made in the design and development of triazole-derived anticonvulsant agents.

A convenient approach to an advanced intermediate toward the naturally occurring, bioactive 6-substituted 5-hydroxy-4-aryl-1H-quinolin-2-ones

An advanced intermediate for the total synthesis of the 5-hydroxy-4-aryl-3,4-dihydro-1H-quinolin-2-one natural products and a 3,4-bisdesoxy analog of peniprequinolone were synthesized.

Current Research on Antiepileptic Compounds

Epilepsy affects about 1% of the world’s population. Due to the fact all antiepileptic drugs (AEDs) have some undesirable side effects and about 30% of epileptic patients are not seizure-free with the existing AEDs, there is still an urgent need for the development of more effective and safer AEDs. Based on our research work on antiepileptic compounds and other references in recent years, this review covers the reported work on antiepileptic compounds which are classified according to their structures. This review summarized 244 significant anticonvulsant compounds which are classified by functional groups according to the animal model data, although there are some limitations in the data. This review highlights the properties of new compounds endowed with promising antiepileptic properties, which may be proven to be more effective and selective, and possibly free of unwanted side effects. The reviewed compounds represent an interesting possibility to overcome refractory seizures and to reduce the percentage of patients with a poor response to drug therapy.

Regioselective one-pot three-component synthesis of quinoline based 1,2,4-triazolo[1,5-a]quinoline derivatives

A one-pot three-component approach for the synthesis of 2-(piperidin-1-yl) quinoline based 1,2,4-triazolo[1,5-a]quinoline derivatives (4a–l) has been described by the reaction of aldehyde (1a–f), methyl 2-cyanoacetate (2) and enaminones (3a–b).

Small molecule screen yields inhibitors of Pseudomonas homoserine lactone-induced host responses

Pseudomonas aeruginosa infections are commonly associated with cystic fibrosis, pneumonias, neutropenia and burns. The P. aeruginosa quorum sensing molecule N-(3-oxo-dodecanoyl) homoserine lactone (C12) cause multiple deleterious host responses, including repression of NF-κB transcriptional activity and apoptosis. Inhibition of C12-mediated host responses is predicted to reduce P. aeruginosa virulence. We report here a novel, host-targeted approach for potential adjunctive anti-Pseudomonal therapy based on inhibition of C12-mediated host responses. A high-throughput screen was developed to identify C12 inhibitors that restore NF-κB activity in C12-treated, lipopolysaccharide (LPS)-stimulated cells. Triazolo[4,3-a]quinolines with nanomolar potency were identified as C12-inhibitors that restore NF-κB-dependent luciferase expression in LPS- and TNF-stimulated cell lines. In primary macrophages and fibroblasts, triazolo[4,3-a]quinolines inhibited C12 action to restore cytokine secretion in LPS-stimulated cells. Serendipitously, in the absence of an inflammatory stimulus, triazolo[4,3-a]quinolines prevented C12-mediated responses, including cytotoxicity, elevation of cytoplasmic calcium, and p38 MAPK phosphorylation. In vivo efficacy was demonstrated in a murine model of dermal inflammation involving intradermalC12 administration. The discovery of triazolo[4,3-a]quinolines provides a pharmacological tool to investigate C12-mediated host responses, and a potential host-targeted anti-Pseudomonal therapy.