Pyranoquinoline Derivatives Research Articles

Synthesis and antibacterial activity of ethyl 2-amino-6-methyl-5-oxo-4-aryl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxylate

Abstract The three-component reaction of 4-hydroxy-1-methyl-2(1 H )-quinolinone, aromatic aldehydes and ethyl cyanoacetate was carried out in the presence of a catalytic amount of 4-dimethyl aminopyridine (DMAP) in aqueous ethanol. The reactions result in the formation of pyranoquinoline derivatives in excellent yields. Antibacterial activity has been evaluated against Gram positive and Gram negative bacteria for some of the synthesized compounds. The results indicated that these compounds are moderately effective against bacterial growth and their effectiveness is highest against Pseudomonas aeruginosa .

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.

Simple, Catalyst-Free, One-Pot Procedure for the Synthesis of 2-Amino-3-cyano-1,4,5,6-tetrahydropyrano[3,2-c]quinolin-5-one Derivatives

A one-pot, three-component reaction of 4-hydroxyquinolin-2(1H)-one, malononitrile, and various aldehydes for the synthesis of 2-amino-3-cyano-1,4,5,6-tetrahydropyrano[3,2-c]quinolin-5-one derivatives is reported. The reaction is performed without any catalysts in a mixed solvent of water and ethanol to give products in good yields. The present method provided a clean, simple, and economical alternative for the synthesis of potential biologically active pyranoquinoline derivatives. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.

Niobium Pentachloride Catalyzed Multicomponent Povarov Reaction

A single-step method for the synthesis of furan- and pyranoquinoline derivatives through multicomponent Povarov reactions between aniline derivatives, benzaldehyde and two different enol ethers (2,3-dihydrofuran and 3,4-dihydropyran) using niobium pentachloride as catalyst under mild conditions, providing good yields and high diastereoselectivity, is described.

ChemInform Abstract: One‐Pot Synthesis of Pyrano‐ and Furanoquinolines Catalyzed by Molten Tetra‐n‐butylphosphonium Bromide under Solvent‐Free Conditions.

AbstractMolten tetrabutylphosphonium bromide is found to be a practical catalytic media for diastereoselective one‐pot synthesis of furano‐ and pyranoquinoline derivatives.

ChemInform Abstract: Synthesis of Some New Pyranoquinoline, Pyridine, and Pyrone Derivatives.

Several new pyrano[3,2-c]quinoline and pyrano[3,2-h]quinoline derivatives has been prepared via reaction of cinnamonitriles with 1-methyl-4-hydroxy-2-quinolone and 8-hydroxyquinoline. Under the same conditions pyridine and pyrone derivatives were also prepared from 2-hydroxyacetophenone

ChemInform Abstract: Efficient and Highly Selective Method for the Synthesis of Benzo(naphtho)quinoline Derivatives Catalyzed by Iodine.

A mild, efficient, and highly selective method for the synthesis of pyranoquinoline and furoquinoline derivatives via a three-component reaction of aromatic aldehyde, naphthalen-2-amine or anthracen-2-amine and 2,3-dihydrofuran, or 3,4-dihydro-2H-pyran catalyzed by iodine is described. It should be noted that exo-isomer was obtained with high selectivity in good yields, which was confirmed by X-ray diffraction analysis. The 3-arylbenzo(naphtha)[f]quinolines were isolated in high yields when the chain n-butylvinyl ether was used as reactant, with the unexpected loss of the butoxy group.

Fast and Efficient Synthesis of Pyrano[3,2-c]quinolines Catalyzed by Niobium(V) Chloride

A highly efficient two-step method for the synthesis of pyranoquinoline derivatives from imino-Diels-Alder reactions be- tween aldimines and 3,4-dihydro-2H-pyran using niobium(V) chlo- ride as catalyst under mild conditions is described.

Ethyl 5-bromo-9-ethoxy-2-oxo-2H-pyrano[2,3-g]quinoline-8-carboxylate

The title compound, C17H14BrNO5, was studied as part of a study on the biological properties of pyranoquinoline derivatives. Alkylation of the parent pyranoquinoline was shown to have occurred at the carbonyl rather than the amino site. The molecules are linked by a C—H...O hydrogen bond forming C(5) chains along [001].

Photochemically Catalyzed Diels—Alder Reaction of N‐Arylimines by 2,4,6‐Triphenylpyrylium Salt: Synthesis of Furo‐ and Pyranoquinoline Derivatives.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Photochemically Catalysed Diels–Alder Reaction of N-arylimines by 2,4, 6-triphenylpyrylium Salt: Synthesis of Furo- and Pyranoquinoline Derivatives

Photochemically promoted Diels–Alder reactions of N-arylimines with 2,3-dihydrofuran and 3,4-dihydro-2 H-pyran were achieved by using 2,4,6-triphenylpyrylium tetrafluoroborate as a catalyst to produce the corresponding furo- and pyranoquinolines in high yield.

Angular methoxy-substituted furo- and pyranoquinolinones as blockers of the voltage-gated potassium channel Kv1.3.

The voltage-gated potassium channel Kv1.3 constitutes an attractive target for immunosuppression because of its role in T-lymphocyte activation and its functionally restricted expression to lymphocytes. Blockade of Kv1.3 channels by margatoxin has previously been shown to prevent T-cell activation and attenuate immune responses in vivo. In the present study, several furo- and pyranoquinoline derivatives were synthesized and screened for their blocking activities of Kv1.3 channels, stably expressed in mice-fibroblasts L929. In addition the activities of the compounds on Kv currents of the neuroblastoma cell line N1E-115 were determined. The most potent compounds, the angular furoquinolinone 8-methoxy-2-(1'-methylethyl)-5-methyl-4,5-dihydrofuro[3,2-c]quinolin-4-one (8c) and the angular pyranoquinolinone 9-methoxy-2,2,6-trimethyl-2,6-dihydro-5H-pyrano[3,2-c]quinolin-5-one (9a), inhibited Kv1.3 channels with half-blocking concentrations of 5 and 10 microM, respectively, and displayed 8-fold (8c) and 2-fold (9a) selectivity over Kv currents of N1E-115 cells. Thus, compounds 8c and 9a might function as a template for the development of novel immunosuppressants.

ChemInform Abstract: Nitriles in Heterocyclic Synthesis. Synthesis and Reactions of Pyrano( 3,2‐h)quinoline Derivatives.

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Predictive structure-activity relationships in a series of pyranoquinoline derivatives. A new primate model for the identification of antiallergic activity

A new primate model has been developed for the evaluation of antiallergic agents. Compounds are tested for their ability to inhibit anti-IgE induced histamine release from the bronchoalveolar mast cells lavaged from the lungs of Macaca arctoides infected with the parasite Ascaris suum. A number of 6-substituted pyranoquinoline derivatives have been evaluated and the activities were subjected to Hansch analysis. A highly significant correlation with lipophilicity (pi) and Hammett sigma p values was obtained. The relationship was used to predict further compounds for synthesis giving rise to new, potent analogues. Some apparently anomalous results could be explained by differences in the ionization of, or tautomerism in, the quinoline ring.

ChemInform Abstract: Nitriles in Heterocyclic Synthesis: Novel Synthesis of Benzo(c)coumarin and of Benzo(c)pyrano(3,2‐c)quinoline Derivatives.

AbstractThe benzo(c)coumarins (IV) are prepared from 3‐cyano‐4‐methylcoumarin (I) and the styryl derivatives (VI) by reaction with the nitriles (II) and (V) respectively.