Shams H. Abdel-Hafez

Selenium-Containing Heterocycles: Synthesis and Pharmacological Activities of Some New 4-Methylquinoline- 2(1H) Selenone Derivatives

Several selenolo[2,3‐b]quinolines and pyrimido[4′,5′:4,5]selenolo[2,3‐b]quinolines were prepared by annulations via reaction of NaSeH with 2‐chloro‐3‐cyano‐4‐methylquinoline 1 followed by reactions with aromatic aldehydes, cycloalkanones, and acetic anhydride. Spectroscopic (IR, 1H‐NMR, and MS) properties of the synthesized compounds are reported. Some selected compounds 5a, 7b, 7c, 8b–d, 9a, 11b, and 11d were investigated for their anti‐inflammatory and analgesic activities; in addition, the most active compounds were tested for their ulcerogenicity and acute toxicity. Moreover, some of the test compounds 7c, 9a, 11b, and 11d were screened for their antibacterial and antifungal activities.

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

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.

Selenium Containing Heterocycles: Synthesis and Pharmacological Activities of Some New Selenolo[2,3-b]quinoline Derivatives and Related Pentacyclic Systems

A new series of selenolo[2,3-b]quinoline, pyrimido[4′,5′:4,5]selenolo[2,3-b]quinoline, pyrimido[4′,5′:4,5]selenolo[2,3-b]-[1,2,4′triazolo[1,5-c]quinoline, and pyrimido[4′,5′:4,5]selenolo[2,3-b][1,2,4]triazolo[4,3-c]quinoline derivatives were prepared starting from diquinolinyl diselenide or 3-cyano-4-methylquinoline-2(1H)selenone with chloro acetonitrile or chloro acetamide. Elemental analysis, IR, 1H NMR, 13C NMR, and mass spectral data confirmed the structure of the newly synthesized compounds. In addition, the most active compounds were tested for their acute toxicity. Moreover, some of the tested compounds were screened for their antibacterial and antifungal activities. The minimum inhibitory concentration (MIC) of the most active compounds was 100 mg mL−1. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Synthesis and Biological Activity of Novel Arylazothiazole Disperse Dyes Containing Selenium for Dyeing Polyester Fibers

GRAPHICAL ABSTRACT Abstract The synthesis of novel heterocyclic aryl monoazo organic compounds, including 3-amino-4,6-dimethyl-N-(5-arylazothiazol-2-yl)selenopheno[2,3-b]pyridine-2-carboxamide, 3-amino-4,6-diphenyl-N-(5-arylazothiazol-2-yl)selenopheno[2,3-b]pyridazine-2-carboxamide and 3-amino-5,6,7,8-tetrahydro-4-(4-methoxyphenyl)-N-(5-arylazothiazol-2-yl)selenopheno[2,3-b]quinoline-2-carboxamide using a condensation reaction involving different 2-(N-chloroacetyl)-5-arylazo-thiazole derivatives with seleno derivatives of pyridine, pyridazine, and/or quinolone, respectively, was undertaken. Analytical and spectroscopic data confirm the proposed structures. The novel synthesized thiazole-selenium disperse dyes were applied for dyeing polyester fabrics. Color characteristics and fastness properties were investigated. The novel synthesized compounds exhibited high efficiency based on in vitro screening of their antioxidant activity, antitumor activity against Ehrlich ascites carcinoma cell EACC cell line and antimicrobial activity against various pathogenic bacteria and fungi. The colored polyester fibers could be applied as sterile and/or biological active fabrics used in various life applications.

One Pot Synthesis of Some New Heteroylselenoglycolic Acids and Their Biological Activity

Abstract A convenient one pot three-stage synthesis was used for obtaining new heteroylselenoglycolic and di-heteroylselenoglycolic acids by nucleophilic substitution reaction of the starting compounds pyridineselenol, pyridazineselenol, and quinolineselenol with α-chloro- or α,α-dichloroacetic acids for 1-h stirring. The newly synthesized compounds were screened biologically for anti-microbial and anti-oxidant activities. The structure of all new compounds was confirmed by 1H NMR, 13C NMR, Mass, and IR spectroscopy and elemental analyses. GRAPHICAL ABSTRACT

Selenium containing heterocycles: Part 1. Synthesis of some new substituted pyrido[3',2':4,5]selenolo[3,2-d]pyrimidines and related fused tetracvclic systems

New series of selenolo[2,3-b]pyridine, pyrido[3′,2′:4,5]selenolo[3,2-d]pyrimidine, 7,8-dihydro-2,4-dimethylpyrrolo [1,2-a]pyrido[3′,2′:4,5]selenolo[3,2-d]pyrimidin-10(6H)-one and 7,9-dimethylpyrido[3′,2′:4,5]selenolo[3,2-d][1,2,4] triazolo[4,3-c]pyrimidine derivatives were synthesised from 3-cyano-4,6-dimethylpyridine-2(1H)-selenone (1). Spectroscopic (IR, 1H, MS) of the newly synthesised compounds are reported.

Design, synthesis and cytotoxic activity of vitamin E bearing selenium compounds against human breast cancer cell line (MCF-7)

GRAPHICAL ABSTRACT ABSTRACT A new series of vitamin E/selenated pyridine, vitamin E/selenated pyridazine, vitamin E/selenated coumarine and vitamin E/selenated nicotine moieties were synthesized and their cytotoxic activity is investigated using the human breast cancer cell line. The newly synthesized compounds were characterized using spectroscopic tools (IR, 1H NMR, 13C NMR, and mass spectroscopy) as well as microanalysis. Our study reveals that compound vitamin E/selenated nicotine moiety has the highest cytotoxic effect than the other synthesized compounds.

Charge-transfer complex of 4-cyano-5,6-diphenylpyridazine-3(2)selenone with picric acid: Infrared, Raman, spectrophotometric, and photostability studies

Change transfer complex of 4-cyano-5,6-diphenylpyridazine-3(2)selenone (CDS) was obtained by reacting of CDS with picric acid. The structure was confirmed by a number of spectral (IR, Raman, UV-Vis) methods. The activation parameters ΔE, ΔH, ΔS, and ΔG were obtained from the DTG diagrams using Coats-Redfern and Horowitz-Metzger methods. The photostability of 4-cyano-5,6-diphenylpyridazine-3(2)selenone (CDS) and its charge-transfer complex doped in polymethyl methacrylate(PMMA) matrix exposed to UV-Vis radiation was studied.

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners.

Summary 3β-Azidocholest-5-ene (3) and (3β)-3-(prop-2-yn-1-yloxy)cholest-5-ene (10) were prepared as substrates to synthesize a variety of three-motif pharmacophoric conjugates through CuAAC. Basically, these conjugates included cholesterol and 1,2,3-triazole moieties, while the third, the pharmacophore, was either a chalcone, a lipophilic residue or a carbohydrate tag. These compounds were successfully prepared in good yields and characterized by NMR, MS and IR spectroscopic techniques. Chalcone conjugate 6c showed the best antimicrobial activity, while the lactoside conjugate 27 showed the best cytotoxic effect in vitro.

Synthesis of some new pyrimidine selanyl derivatives

GRAPHICAL ABSTRACT ABSTRACT The targeted synthesis of 2-(methylsulfanyl)-6-(furan-2-yl)-4(3H)-selenoxo -pyrimidine-5-carbonitrile failed due to the formation 1-methyl-2-methylsulfanyl-6-oxo -4-(furan-2-yl)-1,6-dihydropyrimidine-5-carbonitrile. A new series of 5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidine-4-yl substituted selanyl derivatives were prepared by the reaction of sodium diselenide with 4-chloro-5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine followed by the reaction with chloroacetic acid derivatives such as ethyl chloroacetate, chloroacetamide or chloroacetonitrile. Hydrazinolysis of ethyl (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine- 4-ylselanyl)acetate with hydrazine hydrate gave the corresponding hydrazino derivative. The latter reacted with ethyl acetoacetate, acetylacetone, diethyl malonate, ethoxymethylenemalononitrile or ethyl 2-cyano-3-ethoxyacetate to afford 5-methyl-2-[2-(5,6,7,8-tetrahydro-1-benzothieno [2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazol-3-one, 1-(3,5-dimethylpyrazol-1-yl)-2- (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)ethanone, 1-[2-(5,6,7,8-tetrahydro -1-benzothieno[2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazolidine-3,5-dione and 5-Amino-1-[2-(5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)acetyl]-1H-pyrazol -4-yl substituted carbonitrile or ethyl carboxylate, respectively. The structure of the novel compounds was confirmed by spectroscopic tools (IR, 1H NMR 13C NMR and mass spectra) and elemental analysis.