Synthesis and in vitro evaluation of substituted tetrahydroquinoline-isoxazole hybrids as anticancer agents

Acridine-Isoxazole and Acridine-Azirine Hybrids: Synthesis, Photochemical Transformations in the UV/Visible Radiation Boundary Region, and Anticancer Activity

Easy-to-handle N-hydroxyacridinecarbimidoyl chloride hydrochlorides were synthesized as convenient nitrile oxide precursors in the preparation of 3-(acridin-9/2-yl)isoxazole derivatives via 1,3-dipolar cycloaddition with terminal alkynes, 1,1-dichloroethene, and acrylonitrile. Azirines with an acridin-9/2-yl substituent attached directly or via the 1,2,3-triazole linker to the azirine C2 were also synthesized. The three-membered rings of the acridine-azirine hybrids were found to be resistant to irradiation in the UV/visible boundary region, despite their long-wave absorption at 320-420 nm, indicating that the acridine moiety cannot be used as an antenna to transfer light energy to generate nitrile ylides from azirines for photoclick cycloaddition. The acridine-isoxazole hybrids linked at the C9-C3 or C2-C3 atoms under blue light irradiation underwent the addition of such hydrogen donor solvents, such as, toluene, o-xylene, mesitylene, 4-chlorotoluene, THF, 1,4-dioxane, or methyl tert-butyl ether (MTBE), to the acridine system to give the corresponding 9-substituted acridanes in good yields. The synthesized acridine-azirine, acridine-isoxazole, and acridane-isoxazole hybrids exhibited cytotoxicity toward both all tested cancer cell lines (HCT 116, MCF7, and A704) and normal cells (WI-26 VA4).

Synthesis, crystal structure, Hirshfeld surface analysis and energy framework calculations of trans-3,7,9,9-tetra-methyl-10-(prop-2-yn-1-yl)-1,2,3,4,4a,9,9a,10-octa-hydro-acridine

The title heterocyclic compound, C20H27N, has been prepared in good yield (72%) via a BiCl3-catalyzed cationic Povarov reaction between N-propargyl-4-methyl-aniline and (±)-citronellal. The X-ray single-crystal study indicates that the structure consists of mol-ecules connected by C-H⋯π contacts to produce chains, which pack in a sandwich-herringbone fashion along the b-axis direction. Hirshfeld surface analysis indicates that H⋯H inter-actions dominate by contributing 79.1% to the total surface. Energy frameworks and DFT calculations indicate a major contribution of dispersive forces to the total inter-action energy.

Design and organocatalytic synthesis of spirooxindole–cyclopentene–isoxazole hybrids as novel MDM2–p53 inhibitors

An organocatalytic 1,6-cycloaddition with exclusive α-regioselectivity to synthesize designed spirooxindole–cyclopentene–isoxazole hybrids as novel MDM2–p53 inhibitors.

(E)-4-(3-Phenylisoxazol-5-yl)but-3-en-2-one

(E)-4-(3-Phenylisoxazol-5-yl)but-3-en-2-one was synthesized via the oxidative ring opening reaction of 2-(5-methylfuran-2-yl)-1-phenylethanone oxime, followed by the iodine mediated isomerization.