Mona E. Ibrahim

Advances in the Chemistry of Aminoisoxazole

Abstract This review article is a survey of the literature on aminoisoxazoles. It describes the methods of synthesis and chemical reactions of aminoisoxazoles as building blocks for the synthesis of polyfunctionalized heterocyclic compounds. GRAPHICAL ABSTRACT

Efficient regioselective synthesis and potential antitumor evaluation of isoxazolo[5,4-b]pyridines and related annulated compounds.

The reaction of 5‐amino‐3‐methylisoxazole with appropriate α,β‐unsaturated ketones gave the corresponding isoxazolo[5,4‐b]pyridines. Treatment of 1 with 2,6‐dibenzylidenecyclohexanone or 2‐benzylidenedimedone afforded the corresponding isoxazolo[5,4‐b]quinoline derivatives. 4,6,8,9‐Tetrahydroisoxazolo[5,4‐b]quinolin‐5‐one derivative was also obtained by multicomponent condensation reaction of 1 with dimedone and benzaldehyde. Heterocyclic annulation of the isoxazolo[5,4‐b]pyridine system was achieved via reaction of 1 with benzylidene derivatives of indandione, quinuclidone, pyrazolone, and oxazolone. A representative of some newly synthesized compounds was evaluated as antitumor agents.

New synthetic approach to coumarino[4,3-b]pyridine systems and potential cytotoxic evaluation

The reaction of 4-aminocoumarin (2) with appropriate α,β-unsaturated ketones gave the corresponding coumarin [4,3-b]pyridines. Thus, treatment of 2 with (E)-3-(4-nitrophenyl)-1-phenylprop-2-en-1-one, (1E,4E)-1,5-diphenylpenta-1,4-dien-3-one, (Z)-ethyl 3-(4-chlorophenyl)-2-cyanoacrylate, and (2E,6E)-2,6-dibenzylidenecyclohexanone (3, 6 and 12) afforded the corresponding coumarino[4,3-b]pyridines 5, 7 and coumarino[4,3-b]quinoline derivatives 13, respectively. Heterocyclic annulations of coumarino [5,4-b]pyridine system were achieved via reaction of 2 (in situ) with benzylidene derivatives of indandione to give 15 which was also obtained by multicomponent condensation reaction of 2 (in situ) with indandione and benzaldehyde. A representative sample of new synthesized compounds was evaluated as cytotoxic agents.Graphical Abstract

Convenient synthesis, antimicrobial evaluation and molecular modeling of some novel quinoline derivatives

ABSTRACT α, β-Unsaturated carbonyl compounds 2a, 2b, 3, and 4 were synthesized by the Knoevenagel condensation between 2-substituted quionoline-3-carboxaldehyde 1a and/or 1b with active methylene compounds. In addition, the synthesis of azlactone is achieved starting from 1a and N-acetylglycine. Synthesis of pyridine, pyrene, and pyrimidine derivatives 6–8 were accomplished via one-pot multicomponent reaction of 1b with acetyl acetone, malononitrile, and ammonium acetate; acetophenone, malononitrile, and NaOH; or acetyl acetone and urea in acidic medium. The new synthesized compounds showed good antimicrobial activities. The DFT calculations have been used to predict the electronic properties of the studied compounds. GRAPHICAL ABSTRACT

Recent advances in the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs

This review highlights the recently cited research data in the literature on the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs and their applications over the period from 2013 to 2017. It covers: synthesis of quinoline ring systems and reactions adopted to construct fused or binary quinoline-cord heterocyclic systems. The biological evaluation and the synthetic applications of the target compounds were illustrated.

Peculiar reaction behavior of 1,3-oxathiolan-5-one toward various reagents: Molecular modeling studies and in vitro antioxidant and cytotoxicity evaluation

ABSTRACT Chemical reactivity of 2-methyl-2-phenyl-1,3-oxathiolan-5-one (1) toward various reagents such as hydroxyaldehyde, ketone, α,β unsaturated carbonyl compounds, heterocyclic amine, hydrazine, and hydrazide to give unpredicative opened and fused heterocyclic systems was investigated. Moreover, treatment of compound 1 with bromoester to afford the respective fused system, 2-methyl-2-phenylfuro[3,2-d][1,3]oxathiol-5(6H)-one (6) was implemented. Besides, 1H–1H nuclear overhauser effect spectroscopy was used for full confirmation of the compound 19. In addition, the density functional theory modeling study outcomes were discussed and all of the new synthesized compounds were evaluated as antioxidants and cytotoxicity assay against hepatocellular carcinoma cell line. GRAPHICAL ABSTRACT

Chemistry of bicyclic [1,3,4]thiadiazole 5-5 systems containing ring-junction nitrogen

This review provides a survey of the advances in the methods of formation and chemical reactivity of bicyclic [1,3,4]thiadiazole 5-5 systems containing ring-junction nitrogen over the period from 1989 to the beginning of 2017.

Vistas in the field of 1,3-oxathiolan-5-ones: Synthesis and chemical reactivity

ABSTRACT This review covers many reports of the applications of multicomponent domino reactions (MDRs) in the synthesis of novel stereocontrolled mercapto-heterocycles from the 1972 up to the end of 2016. The reported approaches were employed for modifications of the oxathiolanone core for new construction of a mercapto-heterocycles scaffold from mercaptoacetyl transfer agent with various reagents. GRAPHICAL ABSTRACT

Recent synthetic aspects on the chemistry of aminocoumarins

Coumarin and their derivatives are important groups of heterocyclic compounds. They have attracted considerable interest because of their great biological importance. This review describes the work on the synthesis and heterocyclization reactions of aminocoumarines. It was found that the cyclocondensation process depended mainly on the chemoselective and regioselectivity states of the enamino skeleton.Graphical Abstract