Pyranoquinoline Derivatives Research Articles

Synthetic Approaches for Pyranoquinolines: A Concise Review

Abstract: The pyranoquinoline frameworks have a wide distribution in natural products and have displayed a great amplitude of biological activities, attracting the attention of synthetic and medicinal chemists due to their usefulness in agrochemical and pharmaceutical industries. Among the twenty possible isomeric pyranoquinoline frameworks, research reports for only six of them that were found during the period of time covered in this review article (i.e. 2000 to 2023). According to the literature reports during this frame of time, the synthesis of pyranoquinoline derivatives was achieved by following three general synthetic approaches [i.e. (i) via multicomponent cyclizations (MCC), (ii) via bimolecular cyclizations (BMC) and via intramolecular cyclizations (IMC)], mediated by catalyst-free conditions or by diverse environmentally friendly catalysts, in which mechanistic proposal was discussed for several of such processes. Additionally, various obtained pyranoquinoline derivatives reported in this review were subjected to diverse biological evaluations, such as Parkinson´s and Alzheimer´s diseases, as antibacterials, antifungals, and anticancer drugs, among others, indicating the promising biological potential of this class of heterocyclic structure.

Development of CuMnxOy (x = 2, and y = 4)-GO heterostructure for the synthesis of pyranoquinoline derivatives

The pyranoquinoline derivatives are synthetically important due to their biological properties. In this research, these derivatives were produced through an environmentally friendly method. This method includes the use of CuMnxOy (x = 2, and y = 4)-GO as a nanocatalyst, which is easy to produce, has excellent performance, cost-effectiveness, and recyclability among its features, and also the use of water as a green solvent. Pyranoquinolines through the one-pot, the multi-component reaction between different derivatives of aryl glyoxal, ethyl cyanoacetate, and 4-hydroxyquinoline-2(1H)-one were synthesized using nanocatalyst, K2CO3, and H2O. Also, the structure of the CuMnxOy-GO nanocatalyst was evaluated and confirmed via different analyses. The distinguishing features of this work compared to previous works are easy workup, recyclability of nanocatalyst, facile synthesis process, and provide high yields of products.

One-pot Synthesis of Pyranoquinoline Derivatives Using a New Nanomagnetic Catalyst Supported on Functionalized 4-Aminopyridine (AP) Silica

Multi-component reactions (MCRs) are important tools in combinatorial chemistry because of their capability to prepare target compounds in high yields with superior atom economy. 1 Heterogeneous ca...

Synthesis, characterization, and in vitro antimicrobial investigation of novel pyran derivatives based on 8-hydroxyquinoline

Background8-Hydroxyquinoline derivatives are known for their extensive applications in the field of analytical chemistry and separation techniques; their complexes with transition metals also exhibit antibacterial and antifungal activity.ResultsIn the present study, we synthesized a new series of pyranoquinoline derivatives and evaluated their antibacterial activities. The structures of the synthesized compounds were characterized by Fourier transform infrared (FT-IR), hydrogen-1 nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and elemental analysis. All the prepared compounds were evaluated in vitro as antimicrobial agents against Gram-positive and Gram-negative bacterial strains (Escherichia coli (ATCC35218), Staphylococcus aureus (ATCC29213), Vibrio parahaemolyticus (ATCC17802), and Pseudomonas aeruginosa (ATCC27853)). The screening test was determined by using the standard protocol of disc diffusion method (DDM).ConclusionWe have synthesized new pyranic compounds bearing an 8-hydroxyquinoline moiety on their structure. The preliminary screening results showed that all the tested compounds have a remarkable inhibitory effect on the growth of the majority of the tested bacterial strains compared to the standard antibiotic (penicillin G), and the chlorinated compound (Q1) is more active against Gram-positive bacteria than Gram-negative bacteria such as the Staphylococcus aureus strain which is the most sensitive. Gram-positive bacteria are responsible for a wide range of infectious diseases, and rising resistance in this group is causing increasing concern. Thus, this study develops novel heterocyclic compound derivatives of 8-hydroxyquinoline that have demonstrated good antibacterial activity against Gram-positive bacteria.Graphical abstract

Synthesis and Computational Studies of Molecular Structure and Vibrational Spectra of 2-Amino-4-(4-Nitrophenyl)-4H-Pyrano-[3,2-H]Quinolines

We have disclosed the synthesis of pyranoquinoline derivatives via a one-pot reaction of 4-nitro benz aldehyde, malononitrile/ethyl cyanoacetate and 8-hydroxyquinoline using 30 mol.% DMAP in ethanol under reflux conditions. The Fourier transform infrared spectra of ethyl 2-amino-4-(4-nitrophenyl)-4H-pyra no[3,2-h]quinoline-3-carboxylate were recorded within the range 4000–400 cm–1. The Hartree–Fock and density functional theory on the 6-311G basis set have been utilized to calculate molecular geometry, vibrational frequencies, atomic charges and thermodynamic parameters. Further, the vibrational energy distribution analysis program was applied to assign the vibrational wavenumbers based on potential energy distribution. The HOMO–LUMO energies, the temperature dependence of the thermodynamic properties, the total electron density, and molecular electrostatic potential maps are also studied.

New pyranoquinoline derivatives as vascular-disrupting anticancer agents

A series of new 4-aryl-pyranoquinoline derivatives with a focus on meta-nitro and meta-halophenyl derivatives were prepared and investigated for their structure-dependent antiproliferative effects on a panel of six human cancer cell lines. The compounds were highly active with nanomolar IC50 values. Some of them even exceeded the activities of known analogs such as LY290181 in vitro while not affecting non-malignant fibroblasts. These most active derivatives led to an increase of reactive oxygen species in cancer cells and to a disruption of their microtubular cytoskeleton by inhibiting tubulin polymerization. They also displayed vascular-disrupting activity in ovo as assessed by chorioallantoic membrane assays.

Cell cycle arrest and induction of apoptosis of newly synthesized pyranoquinoline derivatives under microwave irradiation

A set of 2-amino-4-aryl-4H-pyrano[3,2-h]quinoline-3-carbonitrile derivatives were prepared via a one-pot, three-component condensation reaction between the substituted hydroxyquinoline derivatives, some aryl and/or hetaryl aldehydes, and malononitrile in an ethanol/piperidine solution in a microwave irradiation environment. The structure of the prepared compounds was instituted on the foundations of their spectral data: IR, 1H NMR, 13C NMR, and MS. Four human cancer cell lines, MCF-7, HCT-116, HepG-2, and A549 were utilized to evaluate the antiproliferative properties of the target compounds in comparison to the positive controls, Vinblastine and Colchicine using the MTT viability assay. The cell cycle arrest behavior, detected by propidium iodide as well as the apoptosis induction, which was monitored by the flow cytometer, using the Annexin V-FITC kits, was investigated. The results illustrated that the potent cytotoxic compounds induce cell cycle arrest at the G2/M phases and trigger apoptosis in the different tested cancer cells. Finally, the structure−activity relationship (SAR) study showcases the substitution of some specific groups at the 4-, 6-, and 9-positions in the prepared 2-amino-4H-pyrano[3,2-h]quinoline derivatives, which indicates that the lipophilicity manipulates the ability of these moieties against the diverse cell lines.

Iodine mediated in situ generation of R-Se-I: application towards the construction of pyrano[4,3-b]quinoline heterocycles and fluorescence properties.

In this paper, we report the iodine mediated in situ generation of R-Se-I and further its application towards the construction of pyrano[4,3-b]quinolin-1-one derivatives. The structural elaboration of 1-chloro-8-methyl-3-phenylbenzo[b][1,6]naphthyridine 6 was successfully achieved by Sonogashira, Suzuki coupling and dehalogenation reactions. Finally, the synthesized compounds 4a, 5a, 5b, 6, and 7a-7c were studied for photophysical properties including UV-absorption, fluorescence, and quantum yield studies. The synthesized pyranoquinoline derivatives showed λmax, Fmax and Φf values in the range of 391-447 nm, 436-486 nm and 0.004-0.301, respectively in chloroform solvent.

Domino reactions between 6-ethyl-5,6-dihydro-4,5-dioxo-4H-pyrano[3,2-c]quinoline-3-carbonitrile and carbon nucleophilic reagents: Synthesis of novel heteroannulated pyridopyranoquinolines

A variety of novel heteroannulated pyrano[3,2-c]quinolines 2–12 was efficiently synthesized via a domino ‘Michael/retro-Michael/nitrile addition/heterocyclization’ reactions between 6-ethyl-5,6-dihydro-4,5-dioxo-4H-pyrano[3,2-c]quinoline-3-carbonitrile (1) and a diversity of carbon nucleophilic reagents. Pyrido[3′,2′:5,6]pyrano[3,2-c]quinolines 2–6 were synthesized from ring opening ring closure reactions of carbonitrile 1 with some methylene active nitrile namely malononitrile, cyanoacetamide, N-phenylcyanoacetamide, (phenylthio)acetonitrile and ethyl cyanoacetate, respectively. Reactions of carbonitrile 1 with dimer malononitrile and cyanoacetohydrazide showed different behavior producing the novel heteroannulated pyranoquinoline derivatives 7 and 8, respectively. Treatment of carbonitrile 1 with some methylene active ketones namely acetylacetone, acetoacetanilide, ethyl acetoacetate and ethyl benzoylacetate afforded pyrido[3′,2′:5,6]pyrano[3,2-c]quinolines 9–12, respectively. Structures of the synthesized products were deduced on the basis of their analytical and spectral data.

Design New Pyrano Quinoline Derivatives and Study of their Anti-Microbial Activity

Design New Pyrano Quinoline Derivatives and Study of their Anti-Microbial Activity

An efficient synthesis of 4H-pyrano quinolinone derivatives catalysed by a versatile organocatalyst tetra-n-butylammonium fluoride and their pharmacological screening.

A new series of indole-based pyranoquinoline derivatives P1–24 has been synthesized by a one-pot cyclocondensation reaction of 2-(4-substituted)phenyl-N-allyl-indole-3-carbaldehydes 1a–d; active methylenes 2a–c; and 4-hydroxy-1-substituted quinolin-2(1H)-one 3a–b catalysed by an organocatalyst tetra-n-butylammonium fluoride (TBAF) in aqueous ethanol. The easy experimental procedure of the reaction leads to excellent yields of pyranoquinoline derivatives. All the compounds were screened against a representative panel of bacteria and fungi. Some of the compounds are found to be equipotent or more potent than standard drugs as evident from the structural activity relationship study.

DABCO as a green catalyst for the synthesis of pyranoquinoline derivatives

In this study, a rapid and convenient synthesis of quinolines was developed. The reaction involves a one-pot synthesis of pyranoquinoline derivatives from aldehyde, malonitrile, and 8-hydroxyquinoline using DABCO as a catalyst at 80 °C in H2O/EtOH as the solvent in good to high yields.

Sulfamic Acid Catalyzed Atom Economic, Eco‐friendly Synthesis of Novel 7‐(Aryl)‐10‐thioxo‐7,9,10,11‐tetrahedro‐6H‐pyrimido‐[5′4′:5,6]pyrano[3,2‐c]quinoline‐6,8(5H)‐dione and its Derivatives

A series of novel 7‐(3‐chloro‐phenyl)‐10‐thioxo‐7,9,10,11‐tetrahedro‐6H‐pyrimido‐[5′4′:5,6] pyrano[3,2‐c]quinoline‐6,8(5H)‐dione derivatives have been synthesized through the multi‐component condensation of aromatic aldehydes, barbituric acid, and 2,4‐dihydroxy quinoline, using heterogeneous sulfamic acid catalyst in water‐ethanol (4:1) solvent system under reflux condition. The present protocol is endowed with charming description such as green synthetic procedure, short reaction time, easy work‐up procedure, and excellent yield and high atom economy of pyranoquinoline derivatives. In this study, sulfamic acid is used as a heterogeneous catalyst that is easily recoverable and recyclable. The proposed multi‐component reaction has been studied with detail mechanism and spectroscopic data. This is one of the potential greener synthetic approaches to build up the series of pyranoquinoline heterocycles.

Efficient method for the synthesis of 3-arylbenzoquinoline, pyranoquinoline, and thiopyranoquinoline derivatives using PEG1000-based dicationic acidic ionic liquid as recyclable catalyst via a one-pot multicomponent reaction

ABSTRACTA series of 3-arylbenzoquinoline, pyranoquinoline, and thiopyranoquinoline derivatives have been synthesized by one-pot, multicomponent reaction of aromatic aldehyde, naphthalen-2-amine, and ketone using polyethylene glycol (PEG1000)–based dicationic acidic ionic liquid as recyclable catalyst with high yields. The PEG ionic liquid and toluene have the advantages of both homogeneous and heterogeneous phases at different temperatures (biphasic conditions at lower temperatures and monophasic at higher temperatures) with the ease of product as well as catalyst separation. Recycling studies have shown that the ionic liquid can be readily recovered and reused several times without significant loss of activity.

Brønsted-acid catalyzed cascade annulations toward the fused pyranoquinoline derivatives

A Brønsted-acid catalyzed tandem annulation reaction of o-ethynylanilines, aldehydes and nitriles was reported, affording functionalized tricyclic pyranoquinoline derivatives with excellent functional groups tolerance. 4-Quinolone derivatives could be generated in the reaction of o-ethynylanilines and aldehydes. The reaction featured with remarkable advantages such as ready availability of the starting materials, free from transition metals and excellent chemoselectivities.

Magnetic Nano Cobalt Ferrite Catalyzed Synthesis of 4<i>H</i>-Pyrano[3,2-<i>h</i>]quinoline Derivatives under Microwave Irradiation

A microwave irradiated magnetically separable nano cobalt ferrite catalyzed green method for the synthesis of 4-phenyl-4H-pyrano[3,2-h]quinolin-2-amine and 2-amino-4-phenyl-4H-pyrano[3,2-h] quinoline-3-carbonitrile derivatives through cyclization of aromatic aldehyde, acetonitrile/malononitrile and 8-hydoxyquinoline is developed and presented in this paper. The cubic magnetic cobalt ferrite nano particles were synthesized by sol-gel citrate precursor method and characterized by FT-IR, XRD, SEM and TEM techniques and the structures of the synthesized pyranoquinoline derivatives were assigned by IR, MASS and 1H NMR techniques. The reaction is carried out in a domestic microwave oven with a heat-resistant microwave safe glass container with a lid.

ChemInform Abstract: Broensted Acidic Ionic Liquid Catalyzed Tandem Reaction of 4‐Hydroxy‐1‐methyl‐2‐quinolone with Chalcone: Regioselective Synthesis of Pyrano[3,2‐c]quinolin‐2‐ones.

AbstractA facile protocol using an acidic ionic liquid as the catalyst allows the synthesis of pyranoquinoline derivatives through tandem cyclization of substrate (I) with chalcones.

ChemInform Abstract: An Efficient Three‐Component Synthesis of Pyranoquinoline Derivatives.

Pyranoquinoline derivatives have been synthesized via three-component reaction of 4-hydroxy-1-methyl-2(1H)-quinolinone and dialkyl acetylenedicarboxylates in the presence of nucleophiles such as alkyl isocyanides and triphenylphosphine.

Efficient Synthesis of Novel Pyranoquinoline Derivatives from Simple Acetanilide Derivatives: Experimental and Theoretical Study of their Physicochemical Properties using DFT Calculations

A convenient reaction of 2-chloroquinoline-3-carbaldehyde derivatives and dimedone in the presence of KF-Al2O3 for the synthesis of useful pyranoquinolines is described. Reasonable yields (41-50%), easily available starting materials and less expensive efficient catalyst are the key features of the present method. A mechanism was proposed for the reaction course. Attribution of the chemical shifts was made with the help of the density functional theory (DFT) calculations. The computed nuclear magnetic resonance (NMR) chemical shifts are in good agreement with available experimental data. The nucleus-independent chemical shift (NICS) values were used as quantitative measures for the relative aromatic character in pyranoquinolines. The calculated NICS values obtained for the phenyl group of pyranoquinoline compounds are smaller than that of benzene.

Synthesis of new pyran and pyranoquinoline derivatives

Various 2-amino-4H-pyran-3-carbonitriles 1 and 2 were successfully synthesized, via a one-pot three-component condensation reaction of arylaldehyde and malononitrile with methyl acetoacetate and 8-hydroxyquinoline, respectively in moderate yields. These key intermediates 1 and 2 undergo rapid condensation with formic acid and acetic anhydride to give, respectively the corresponding pyranes 3–6 and pyranopyrimidinones 7 and 8. All the synthesized compounds were completely characterized by 1H NMR, 13C NMR, IR and ES-HRMS.