El-Sayed I. Ibrahim

Bio: El-Sayed I. Ibrahim is an academic researcher from Suez Canal University. The author has contributed to research in topics: Quinoline & Dimedone. The author has an hindex of 6, co-authored 14 publications receiving 91 citations. Previous affiliations of El-Sayed I. Ibrahim include Tanta University.

Chapter 1 Dimedone: A Versatile Precursor for Annulated Heterocycles

Abstract: Publisher Summary This chapter explores that dimedone is a versatile precursor for annulated heterocycles. Dimedone(1) is an alicyclic compound having 1,3-dicarbonyl groups flanked by a methylene group and exists in a tautomeric transenolized form where intramolecular hydrogen bonding is not possible. Dimedone is an excellent precursor for partially hydrogenated fused heterocycles where two of the carbon atoms of dimedone are part of the backbone of the formed heterocycles. The chapter illustrates that dimedone's structural features and its reactivity to form more functionalized derivatives have led to the construction of a wide range of fused or spiral biheterocycles. Finally, this chapter emphasizes the role of 1 in the synthesis of fused heterocycles, classified according to the size of the ring and the number of heteroatoms in the heterocycle fused to the cyclohexane ring and subdivided according to the heteroatoms and their arrangement in the ring.

Microwave irradiation for accelerating the synthesis of acridine and xanthene derivatives from dimedone

Abstract: Microwave (MW) irradiation activated the reaction of dimedone with aniline or p-chloroaniline in formic acid to give the acridine derivatives 2a and 2 b, respectively, which can be derivatized as the bisoximes 3 and bisphenylhydrazone 4. However, under the same reaction conditions 2- aminopyridine gave the xanthene derivative 6 and not the expected acridine derivative 2c. When 2-aminopyridine was allowed to react under MW irradiation with dimedone in presence of benzaldehyde in ethanol it gave the bis(dimedonyl)methane derivative 10. Cyclization of 10 has been enhanced under MW irradiation to give the xanthene derivative 9 in improved yield and in less time than the conventional heating. The structures of products were confirmed from the analysis of their IR, 1 H-NMR and mass spectra. The antimicrobial activity has been investigated for compounds 3, 4, 6 and 10.

Synthesis of Some New Pyridines, Thienopyridines and Pyrido[2,3:4',5']thieno[3',2'-d]pyrimidin-8-ones from 2 acetylbenzoimidazole

Abstract: Reaction of 2-acetylbenzoimidazole 1 with some arylaldehydes under different conditions gave chalcones, 1,5-pentanediones and pyridines. Treatment of chalcones with various types of reagents gave the corresponding new pyridines, thienopyridines, pyrido[2,3:4',5']thieno[3',2'-d]-pyrimidin-8-ones via initial addition of active methylene or amino group to the double bond followed by cyclization.

Synthesis of some quinolinyl chalcone analogues and investigation of their anticancer and synergistic anticancer effect with doxorubicin.

Abstract: Two derivatives of 2-(4-acetylanilino)quinolines (IIIa, b) were synthesized as scaffolds for synthesis of open chalcone analogues (Va-f) through Claisen-Schmidt condensation with a set of aromatic aldehydes (IVa-d). Derivatives (Va, b) were further manipulated into cyclic alpha,beta-unsaturated ketones by Michael-addition of acetylacetone and ethylacetoacetate affording derivatives (VI-VII). Deethoxycarboxylation of derivatives (VIIa, b) afforded cyclohexenons (VIIIa, b) allowing formation of a mini library of alpha,beta-unsaturated ketones for screening their anticancer and synergistic anticancer effect with doxorubicin using colon cancer cell line (Caco-2). Two open enones, (Vb) and (Ve), showed significant anticancer activity with IC50 of 5.0 and 2.5 microM respectively. Only one cyclic enone, (VIa) showed synergistic anticancer activity with doxorubicin at 10 microM.

Heteropolyacid (H3PW12O40) supported MCM-41: An efficient solid acid catalyst for the green synthesis of xanthenedione derivatives

Abstract: HPWA/MCM-41 mesoporous molecular sieves of appropriate ratios were prepared by loading HPWA on siliceous MCM-41 by the wet impregnation method. The prepared HPWA/MCM-41 materials were characterized by X-ray diffraction analysis (XRD) and BET surface area and FT-IR measurements. The morphology of mesoporous materials was studied by TEM observation. The catalytic activity of the above materials was tested for the condensation of dimedone (active methylene carbonyl compound) and various aromatic aldehyes under liquid phase conditions at 90 °C. The products were confirmed by FT-IR, 1H NMR and 13C NMR studies. HPWA supported MCM-41 catalysts catalyses efficiently the condensation of dimedone and aromatic aldehydes in ethanol and other solvents under liquid phase conditions to afford the corresponding xanthenedione derivatives. Activities of the catalysts follow the order: HPWA/MCM-41(20 wt.%) > HPWA/MCM-41(30 wt.%) > H3PW12O40·nH2O > HPWA/MCM-41(10 wt.%) > HPWA/SiO2 (20 wt.%) > HM (12) > Hβ (8) > Al-MCM-41 (50). Various advantages associated with these protocols include simple workup procedure, short reaction times, high product yields and easy recovery and reusability of the catalyst.

Acyclonucleosides: Part 2. diseco-Nucleosides*

Abstract: This chapter is the second of a sequence of three chapters that appears in successive volumes of this series dealing with the chemistry of acyclonucleosides. The first chapter appeared in the previous volume [97AHC391] and dealt with seco-nucleosides (one bond disconnection). This chapter deals with diseco-nucleosides (two bond disconnections). The final chapter of this series will deal with tri-, tetra-, and pentaseco-nucleosides, as well as contain an appendix of the literature that appeared after the three chapters were prepared.

张礼和院士、周德敏教授应邀分别担Eur.J.Med.Chem.杂志和J.Med.Chem.杂志的编委

Abstract: 《中国药学》（英文版）主编张礼和院士应欧洲药物化学会的邀请，自2014年起担任药学领域国际权威杂志Eur．，Med．Chem．杂志的副主编，这是中国科学家首获此殊荣。创刊于1966年的欧洲药物化学杂志是国际上权威的药物研究杂志，报道当前药物化学前沿的所有领域。张礼和院士担此重任，既是他数十年药物化学研究成就的体现，也反映当前中国药物化学研究崛起的现状。

Molecular targets and anticancer activity of quinoline–chalcone hybrids: literature review

Abstract: α,β-Unsaturated chalcone moieties and quinoline scaffolds play an important role in medicinal chemistry, especially in the identification and development of potential anticancer agents. The multi-target approach or hybridization is considered as a promising strategy in drug design and discovery. Hybridization may improve the affinity and potency while simultaneously decreasing the resistance and/or side effects. The conjugation of quinolines with chalcones has been a promising approach to the identification of potential anticancer agents. Most of these hybrids showed anticancer activities through the inhibition of tubulin polymerization, different kinases, topoisomerases, or by affecting DNA cleavage activity. Accordingly, this class of compounds can be classified based on their molecular modes of action. In this article, the quinolone–chalcone hybrids with potential anticancer activity have been reviewed. This class of compounds might be helpful for the design, discovery and development of new and potential multi-target anticancer agents or drugs.