Experimental and theoretical study on one-pot, three-component route to 2H-indazolo[2,1-b]phthalazine-triones catalyzed by nano-alumina sulforic acid

Ag NPs supported chitosan-agarose modified Fe3O4 nanocomposite catalyzed synthesis of indazolo[2,1-b]phthalazines and anticancer studies against liver and lung cancer cells

In this article we report a novel Ag NPs fabricated chitosan-agarose composite functionalized core-shell type Fe₃O₄ nanoparticle (Ag/CS-Agar@Fe₃O₄). The biogenic material was analyzed over a number of physicochemical methods like, FT-IR, FE-SEM, TEM, EDX, XRD, VSM and ICP-OES. In catalytic exploration we aimed the synthesis of diverse 2H-indazolo0-b]phthalazine-trione derivatives via one-pot three component coupling of phathalalhydrazide, dimedone and different aldehydes. It afforded good to excellent yields under solvent-less conditions. Robustness of the catalyst was justified by catalyst recyclability for consecutive 10 times, hot filtration and leaching tests. Again, biological activity of the material was evaluated by studying the antioxidant and cytotoxicity properties over lung and liver cancer cell lines. Antioxidant potential of Ag/CS-Agar@Fe₃O₄ was assessed by DPPH radical scavenging studies and the corresponding IC50 was found to be 96.57 μg/mL. Liver and lung cancer studies over Ag/CS-Agar@Fe₃O₄ was carried out by MTT assay against HepG2 and A549 cell lines. The corresponding IC50 values were found as 192.35 and 365.28 μg/mL respectively. % Cell viability of the nanomaterial decreased dose dependently over both the cell lines without any cytotoxicity on normal cell line. The results demonstrates Ag/CS-Agar@Fe₃O₄ nanocomposite to be an efficient chemotherapeutic drug against the lung and hepatocellular carcinoma cells.

[TBP]2SO4 ionic liquid catalyst for 4MCR of pyridazinoindazole, indazolophthalazine and pyrazolophthalazine derivatives

Tetrabutyl phosphonium sulfate ([TBP]₂SO₄), as novel room-temperature ionic liquid (RTIL), was synthesized by a simple cost-effective method, characterized by ¹H, ¹³C, ³¹P NMR and FT-IR spectrophotometry. The newly prepared catalyst was used as an efficient catalyst in some four multicomponent reactions (4MCRs) e. g., to synthesis pyridazino[1,2-a]indazole, indazolo[2,1-b]phthalazine and pyrazolo[1,2-b]phthalazine. This green method has several advantages such as short reaction time, using simple methods to prepare catalysts and products, easy operation and high efficiency of products. In addition, the catalyst can be easily recovered and reused several times with reduced average activity.

Ag NPs on chitosan-alginate coated magnetite for synthesis of indazolo[2,1-b]phthalazines and human lung protective effects against α-Guttiferin

Biocomposite nanomaterials have been evolved as the new generation catalysts and therapeutic supplement in these days. Magnetically isolation has added new features to this category. This has encouraged us to synthesize a novel Ag NP adorned chitosan-alginate dual bio-polysaccharide (two of the more versatile polysaccharides) modified core-shell magnetic nanocomposite (Fe₃O₄/CS-Alg/Ag NPs). The material was meticulously characterized following different physicochemical techniques, such as, FT-IR, ICP-OES, FESEM, EDX, atomic mapping, TEM, VSM, XRD and XPS studies. The as synthesized material was catalytically explored in the one-pot multicomponent synthesis of biologically potent 2H-indazolo[2,1-b]phthalazine-trione derivatives involving a wide range of substrates. The reactions were ended up with excellent yields under solvent-free heating conditions. The catalyst recyclability, heterogeneity and leaching tests were performed to ensure its high stability and robustness. It could be reused as much as 10 times in succession with almost unchanged catalytic performances. In the lung protective part of the present research, the human lung toxicity was induced by α-Guttiferin. The cell viability of lung MRC-5, CCD19Lu, WI-38, and BEAS-2B cell lines was measured by trypan blue assay. Caspase-3 activity was assessed by the caspase activity colorimetric assay kit and mitochondrial membrane potential of lung cells was studied by Rhodamine123 fluorescence dye. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test was used to show DNA fragmentation and apoptosis of lung cells. Also, the Rat inflammatory cytokine assay kit was used to measure the concentrations of inflammatory cytokines. The catalyst-treated cell cutlers significantly (p ≤ 0.01) reduced the DNA fragmentation, caspase-3 activity, and inflammatory cytokines concentrations, and raised the mitochondrial membrane potential and cell viability in the high concentration of α-Guttiferin-treated lung MRC-5, CCD19Lu, WI-38, and BEAS-2B cells. The best result of lung protective properties of catalyst against α-Guttiferin was seen in the high dose of catalyst i.e., 4 μg. DPPH test revealed similar antioxidant potentials for catalyst and butylated hydroxytoluene. The catalyst inhibited half of the DPPH molecules in the concentration of 171 μg/mL. According to the above results, catalyst can be administrated as a lung protective drug for the treatment of lung diseases after approving in the clinical trial studies in humans.

Preparation, characterization, and use of novel Cu@Fe3O4 MNPs in the synthesis of tetrahydrobenzimidazo[2,1-b]quinazolin-1(2H)-ones and 2H-indazolo[2,1-b]phthalazine-triones under solvent-free conditions

Cu@Fe₃O₄ MNPs as novel nanomagnetic reagents were prepared to investigate their catalytic behavior in the preparation of tetrahydrobenzimidazo[2,1-b]quinazolin-1(2H)-ones, as important biologically active compounds. Then, characterization of the synthesized nanoparticles was performed using different methods including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). All reactions were performed with small amounts of the Cu@Fe₃O₄ MNPs under solvent-free conditions. After completion of the reaction, because of the magnetic nature of the nanocatalyst, they could be simply separated with an external magnet and easily reused with no considerable decrease in the catalytic behavior even after seven runs.

A new efficient domino approach for the synthesis of pyrazolyl-phthalazine-diones. Antiradical activity of novel phenolic products

Pyrazolyl-phthalazine-dione derivatives (PPDs) were synthetized in the ionic liquid catalyzed one-pot multicomponent reaction of acetylacetone, 2,3-dihydrophthalazine-1,4-dione, and different aldehydes in moderate to good yields. Six new PPDs were obtained, and the crystal structure of 2-acetyl-1-(4-fluorophenyl)-3-methyl-1H-pyrazolo[1,2-b]phthalazine-5,10-dione (PPD-4) was determined. The most interesting structural features of the novel PPD-4 is the formation of a rather short intermolecular distance between the F atom of one molecule and the midpoint of the neighbouring six-membered heterocyclic ring. This interaction arranges all molecules into parallel supramolecular chains. UV-Vis spectra of all PPDs were acquired and compared to the simulated ones obtained with TD-DFT. All synthetized compounds were subjected to evaluation of their in vitro antioxidative activity using a stable DPPH radical. It was shown that PPD-7, with a catechol motive, is the most active antioxidant, while PPD-9, with two neighbouring methoxy groups to the phenolic OH, exerted a somewhat lower, but significant antioxidative potential. The results of DFT thermodynamical study are in agreement with experimental findings that PPD-7 and PPD-9 should be considered as powerful radical scavengers. In addition, the obtained theoretical results (bond dissociation and proton abstraction energies) specify SPLET as a prevailing radical scavenging mechanism in polar solvents, and HAT in solvents with lower polarity. On the other hand, the obtained reaction enthalpies for inactivation of free radicals suggest competition between HAT and SPLET mechanisms, except in the case of the ˙OH radical in polar solvents, where HAT is labeled as prefered.

An efficient one-pot method for the synthesis of pyrazolyl-phthalazine-diones was developed. New phenolic compounds exerted good to excellent antioxidative activity.

Introduction of Fe3O4@SiO2–ZrCl2-MNPs for the efficient promotion of some multi-component reactions under solvent-free conditions

In the work, the preparation, characterization and use of Fe₃O₄@SiO₂–ZrCl₂-MNPs as nano magnetic reagents in the promotion of some multi-component reactions is reported.

SO3H-functionalized mesoporous silica materials as solid acid catalyst for facile and solvent-free synthesis of 2H-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives

SO₃H-functionalized mesoporous silica materials were used to synthesize 2H-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives in a one-pot three-component condensation reaction.

Synthesis of heterocycles and fused heterocycles catalyzed by nanomaterials

The application of nanomaterials as heterogeneous catalyst for the synthesis of different heterocyclic systems is reviewed.

Nano Brönsted solid acid containing double-charged diazoniabi-cyclo[2.2.2]octane chloride supported on nano rice husk silica: an efficient catalyst for the one-pot synthesis of phthalazine compounds

In the present work, amorphous silica nanoparticles were synthesized from low-cost rice husk ash (RH–SiO₂).