Recent synthetic methodologies for the tricyclic fused-quinoline derivatives

Six-Membered Aromatic Nitrogen Heterocyclic Anti-Tumor Agents: Synthesis and Applications

Cancer stands as a serious malady, posing substantial risks to human well-being and survival. This underscores the paramount necessity to explore and investigate novel antitumor medications. Nitrogen-containing compounds, especially those derived from natural sources, form a highly significant category of antitumor agents. Among these, antitumor agents with six-membered aromatic nitrogen heterocycles have consistently attracted the attention of chemists and pharmacologists. Accordingly, we present a comprehensive summary of synthetic strategies and clinical implications of these compounds in this review. This entails an in-depth analysis of synthesis pathways for pyridine, quinoline, pyrimidine, and quinazoline. Additionally, we explore the historical progression, targets, mechanisms of action, and clinical effectiveness of small molecule inhibitors possessing these structural features.

Discovery of new pyrimido[5,4-c]quinolines as potential antiproliferative agents with multitarget actions: Rapid synthesis, docking, and ADME studies

A novel series of pyrimido[5,4-c]quinoline derivatives variously substituted at positions 2 and 5 have been synthesized, in good to excellent yields, via rapid base-catalyzed cyclization reaction of 2,4-dichloroquinoline-3-carbonitrile (5) with guanidine hydrochlorides 6a-c. All the synthesized compounds were screened for their in vitro antiproliferative activity. The most active hybrids 26a-d, 28a-d, and 30B were assessed against topoisomerase (topo) I, topo IIα, CDK2, and EGFR. The majority of the tested compounds exhibited selective topo I inhibitory activity while had weak topo IIα inhibitory action with compounds 30B and 28d, showed better topo I inhibitory activity than the reference camptothecin. Compound 30B, the most potent derivative as antiproliferative agent, exhibited moderate activity against CDK2 (IC₅₀ = 1.60 µM). The results of this assay show that CDK2 is not a potential target for these compounds, implying that the observed cytotoxicity of these compounds is due to a different mechanism. Compounds 30B, 28d, and 28c were found to be the most potent against EGFR and their EGFR inhibitory activities (IC₅₀ = 0.40 ± 0.2, 0.49 ± 0.2, and 0.64 ± 0.3, respectively) relative to the positive control erlotinib (IC₅₀ = 0.07 ± 0.03 µM). These results revealed that topo I and EGFR are attractive targets for this class of chemical compounds.

Electrochemical Selective C3-Thiolation of Quinolines

An electrochemical method has been developed to achieve C3-thiolation of quinoline compounds. This new strategy highlights the maximum atom economy, direct conversion and also the use of simple and readily...

Synthesis of quinolines via sequential addition and I2-mediated desulfurative cyclization

An efficient one-pot approach for the synthesis of quinolines from o-aminothiophenol and 1,3-ynone under mild conditions is disclosed. With the aid of ESI-MS analysis and parallel experiments, a three-step mechanism is proposed—a two-step Michael addition–cyclization condensation step leading to intermediate 1,5-benzothiazepine catalyzed by zirconocene amino acid complex Cp₂Zr(η¹-C₉H₁₀NO₂)₂, followed by I₂-mediated desulfurative step.

An efficient one-pot approach is proposed for the synthesis of quinolines through Lewis acid-catalyzed cyclization and iodine-mediated desulfurization reactions.