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Dive into the research topics where H. A. H. El-Sherief is active.

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Featured researches published by H. A. H. El-Sherief.


Synthetic Communications | 2006

Utility and Synthetic Uses of Mannich Reaction: An Efficient Route for Synthesis of Thiadiazino‐[1,3,5][3,2‐a]benzimidazoles

Abd El-Wareth A. O. Sarhan; Shams H. Abdel-Hafez; H. A. H. El-Sherief; Tarek Aboel‐Fadl

Abstract The utilities of the Mannich reaction in synthetic organic chemistry are reviewed. The behaviors of Mannich reactions on several bifunctional heterocyclic compounds have been reported. A new class of heterocyclic compounds, thiadiazino[1,3,5][3,2‐a]benzimidazoles 12a–g, were obtained by reaction of 2‐mercaptobenzimidazole with primary aliphatic amines in a one‐step synthesis. An attempt to apply this reaction using primary aromatic amines lead to the formation of the well‐known Mannich bases 11a–g rather than the N‐substituted thiadiazines 13.


Journal of Chemical Research-s | 1997

Studies on the Synthesis and Cyclization Reactions of2-(5-Amino-3-arylpyrazol-1-yl)-3-methylquinoxalines

H. A. H. El-Sherief; A. M. Mahmoud; Ahmed A. Ismaiel

A series of2-(5-amino-3-arylpyrazol-1-yl)-3-methylquinoxalines (2a–d)has been synthesized by the condensation of2-hydrazino-3-methylquinoxaline (1) with substitutedbenzoylacetonitriles and converted into the corresponding3,4-diaryl-1-(3-methylquinoxalin-2-yl)-4,8-dihydro-1H -pyrazolo[3,4-e ][1,4]thiazepin-7(6H )-ones(7a–d) and2-(3-aryl-4,5,6,7-tetrahydro-5-alkyl/aryl-1H -pyrazolo[3,4-d ]pyrimidin-1-yl)-3-methylquinoxalines(8a–e).


Zeitschrift für Naturforschung B | 1997

A Convenient One-Pot Synthesis of Pyrazolo[3,4-d]pyrimidines and s-Triazolo[3,4-b][1,3,5]thiadiazines

Zeinab A. Hozien; Abd El-Wareth A. O. Sarhan; H. A. H. El-Sherief; A. M. Mahmoud

Abstract The reaction of 5-amino-3-aryl-1-phenylpyrazoles (1a-d) with formaldehyde and secondary amines in boiling ethanol gave the corresponding 4-alkylaminomethyl derivatives (2a-f) and bis-(4-pyrazolyl)methane (4a,b) as byproduct. Such reaction with primary aliphatic and aro matic amines at room temperature afforded 1,3,5-trisubstituted (5a-h) and 1,3.5,7-tetrasubstituted tetrahydropyrazolo[3,4-d]pyrimidines (8a-k) respectively in good yield. Similarily, the Mannich reaction of 5-mercapto-3-phenyl-1,2,4-triazole (9) with secondary amines, in boiling ethanol, and primary aromatic amines, at room temperature, gave 2 -substituted aminomethyl derivatives (10a-c) and (14a-g) respectively,while with primary aliphatic amines, p-toluidine and p-anisidine,at room temperature,and with other primary aromatic amines, in boiling ethanol, afforded the cyclized products 12,4-triazolo[3,4-b]thiadiazines (13a-e); (15f,g) and (15a-e), respectively.


RSC Advances | 2016

An efficient and rapid intramolecular cyclization of a quadruple Mannich reaction for one-pot synthesis of pentaazaphenalenes and their antimicrobial activities

Ahmed F. M. El-Mahdy; H. A. H. El-Sherief

A simple, rapid and one-pot quadruple Mannich reaction has been developed for the synthesis of 2,5,7,9,11-pentaazaphenalenes via a three-component reaction of 6-amino-2-thioxo-2,3-dihydropyrimidin-4(1H)-one, formaldehyde and primary amines in ethanol at room temperature. The reaction products were obtained in very good to excellent yields using a simple work-up procedure. The regioselectivity of the reaction was studied using the electronic energy calculations which indicated that the corresponding products 2,5,7,9,11-pentaazaphenalenes are more favorable than the other isomeric products 3,5,8,10,11-pentaazaanthracenes and 2,5,7,8,10-pentazaphenanthrenes. The reaction mechanism was investigated and the structures of all the new compounds were confirmed using spectra and elemental analysis. In addition, all the synthesized compounds were screened for antimicrobial activity and showed a significant activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, Geotrichum candidum and Trichophyton rubrum.


Journal of Heterocyclic Chemistry | 2000

An efficient route for synthesis of 5,6‐diphenylimidazo‐[2,1‐b]thiazoles as antibacterial agents

Zeinab A. Hozien; A. O. Sarhan Abd El-Wareth; H. A. H. El-Sherief; A. M. Mahmoud


Bulletin of the Chemical Society of Japan | 1983

Synthesis of the 1,2,4-triazolo(4,3-a)quinazolin-5-ones and related compounds.

H. A. H. El-Sherief; A. E. Abdel-Rahman; G. M. El-Naggar; A. M. Mahmoud


Journal of Heterocyclic Chemistry | 1984

Substitution and ring closure reactions of phthalazine derivatives

M. Z. A. Badr; H. A. H. El-Sherief; G. M. El-Naggar; S. A. Mahgoub


Bulletin of the Chemical Society of Japan | 1983

Reaction of Quinoxaline Derivatives with Nucleophilic Reagents

M. Z. A. Badr; Galal Mohamed El-Naggar; H. A. H. El-Sherief; Abdou El-Sayed Abdel-Rahman; Moustafa Fouzy Aly


Arkivoc | 2011

One pot synthesis and reactions of novel 5-amino[1,3]thiazolo[3,2-b][1,2,4]triazoles

H. A. H. El-Sherief; Zeinab A. Hozien; Ahmed F. M. El-Mahdy; A. A. O. Sarhan


Journal of Applied Chemistry and Biotechnology | 2007

Thermolysis of mono-, di- and tri-benzylamines, IV

M. Zarif A. Badr; M. M. Aly; H. A. H. El-Sherief; Abdo E. Abdel Rahaman

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