Organics

In the present work, we describe the synthesis of a new heterocyclic derivative, 2-(naphthalen-1-yl)-2,3,5,6-tetrahydro-1H-isoquinolino[8,1,2-hij]quinazoline 1, using the reaction between the aminal 1,3,6,8-tetraazatricyclo[4.4.1.1^3,8]dodecane 2 (TATD) and 1-naphthylamine 3 as the first scaffold of a four-step linear synthetic route. In the first step, a condensation catalyzed by acetic acid in 96% ethanol was carried out, leading to the formation of the intermediate 3-(naphthalen-1-yl)-1,2,3,4-tetrahydrobenzo[h]quinazoline 4. Subsequently, this intermediate was acylated with 2-chloroacetyl chloride in the presence of triethylamine and under an inert atmosphere, obtaining the compound 2-chloro-1-(3-(naphthalen-1-yl)-3,4-dihydrobenzo[h]quinazolin-1(2H)-yl)ethan-1-one 5. In the third step, an intramolecular Friedel–Crafts cyclization was carried out using aluminum trichloride as a catalyst, yielding 2-(naphthalen-1-yl)-1,2,3,6-tetrahydro-5H-isoquinolino[8,1,2-hij]quinazolin-5-one 6. Finally, the reduction of this lactam with phosphorus pentachloride and sodium borohydride under anhydrous conditions led to the further closure of the polycyclic system, yielding the final product 1. The proposed route demonstrates the feasibility of using TATD 2 as a versatile precursor for constructing condensed heterocyclic systems of structural interest and potential relevance in advanced organic synthesis.

2-Aryl-2-(3-indolyl)acetohydroxamic acids have emerged as promising antitumor agents; however, their poor pharmacokinetic profile remains a significant drawback. To address this limitation, we have synthesized a homolog of such acids—specifically 2-aryl-2-(3-indolyl)propionic acid (IC₅₀ > 100 mM (U87)), along with several other derivatives: ethyl ester (IC₅₀ > 100 mM (U87)), hydroxamate (IC₅₀ 21.2 ± 1.0 mM (U87)) and hydrazide (IC₅₀ > 100 mM (U87)). The cytotoxicity of these compounds against glioblastoma cell lines was evaluated and compared to that of the parent acetohydroxamic acid derivatives.

Understanding Li⁺ solvation structure is critical for the rational design of high- and localized high-concentration electrolytes. Here, we present a systematic investigation of tetrahydrofuran (THF)-based electrolytes with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) using Raman spectroscopy and ⁷Li nuclear magnetic resonance to investigate the local solvation structures. By varying the THF:LiTFSI molar ratio, we observed a transition of Li⁺ solvation from solvent-separated ion pairs to contact ion pairs and aggregates, accompanied by increased structural heterogeneity and constrained local dynamics. Raman spectroscopy captures the evolution of Li⁺–anion coordination with increasing salt concentration, while ⁷Li NMR chemical shifts, line widths, and relaxation times provide complementary insight into changes in the electronic environment and symmetry of Li⁺ coordination. Electrolyte structure is further examined by introducing a hydrofluoroether co-solvent into a concentrated (THF)₂–LiTFSI electrolyte. Raman results show that the local Li⁺–TFSI⁻ coordination structure is preserved upon 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) addition, whereas NMR reveals subtle modifications of the ion-rich solvation clusters. These results provide fundamental insight into Li⁺ solvation and electrolyte localization, offering general design principles for advanced electrolyte systems.