Ahmad M. Farag

Synthesis of new N-phenylpyrazole derivatives with potent antimicrobial activity

The versatile synthons 4-(2-bromoacetyl)-5-methyl-1-phenyl-3-phenylcarbamoyl-1H-pyrazole (3) and 4-[(E)-3-(dimethylamino)acryloyl]-5-methyl-1-phenyl-3-phenylcarbamoyl-1H-pyrazole (2) were used as precursors for the synthesis of a series of phenylpyrazoles with different aromatic ring systems at position 4. The antimicrobiological evaluation of the newly synthesized compounds was carried out in vitro assays for antifungal and antibacterial activities. Amongst the tested compounds, 4-acetyl-5-methyl-1-phenyl-3-phenylcarbamoyl-1H-pyrazole (1), 4-[(E)-3-(dimethylamino)acryloyl]-5-methyl-1-phenyl-3-phenylcarbamoyl-1H-pyrazole (2), 4-(2-bromoacetyl)-5-methyl-1-phenyl-3-phenylcarbamoyl-1H-pyrazole (3) and 4-(2-aminothiazol-4-yl)-5-methyl-1-phenyl-3-phenylcarbamoyl-1H-pyrazole (17) showed interesting antimicrobial properties. In particular, all tested compounds produced inhibitory effects against pathogenic yeast (Candida albicans) similar or superior to those of reference drug. In addition, compound 3 showed excellent activity against pathogenic mould (Aspergillus). From structure-activity relationship (SAR) point of view, the attachment of bromoacetyl moiety to pyrazole ring can be considered as a breakthrough in developing a new therapeutic antifungal agent related to phenylpyrazole system.

Design, synthesis and structure-activity relationship study of novel pyrazole-based heterocycles as potential antitumor agents.

The versatile hitherto unreported 3-[(E)-3-(dimethylamino)acryloyl]-1,5-diphenyl-1H-pyrazole-4-carbonitrile (3) was prepared via the reaction of 3-acetyl-1,5-diphenyl-1H-pyrazole-4-carbonitrile (1) with dimethylformamid-dimethylacetal (DMF-DMA). The latter product and 3-((E)-3-morpholin-4-yl-acryloyl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile (4) underwent regioselective 1,3-dipolar cycloaddition with nitrilimines to afford the corresponding pyrazole derivatives. In vivo anti-estrogenic activity and acute toxicity after single oral dose of the newly synthesized compounds were evaluated. In vitro disease-oriented primary antitumor screening utilizing 14 cell lines of breast and ovarian tumor subpanels has been also carried out. All tested compounds showed anti-estrogenic properties equipotent or superior to the reference drug, letrozole. 3-[3-(4-Cyano-1,5-diphenyl-1H-pyrazole-3-yl)-1-(4-methylphenyl)-1H-pyrazole-4-carbonyl]-1,5-diphenyl-1H-pyrazole-4-carbonitrile (27c) and 3-(3-acetyl-1-phenyl-1H-pyrazole-4-carbonyl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile (8a) showed a significant cytotoxic activity in a nanomolar range against certain types of breast and ovarian tumors with tolerable toxicity.

Synthesis and analgesic/anti-inflammatory evaluation of fused heterocyclic ring systems incorporating phenylsulfonyl moiety

A series of pyrazolo[1,5-a]pyrimidine, triazolo[1,5-a]pyrimidine, and pyrimido[1,2-a]benzimidazole ring systems incorporating phenylsulfonyl moiety were synthesized via the reaction of 3-(N,N-dimethylamino)-1-aryl-2-(phenylsulfonyl)prop-2-en-1-one derivatives 2a,b with appropriate nitrogen nucleophiles. The analgesic and anti-inflammatory activities of the newly synthesized compound were investigated in vivo. 3-Bromo-2-phenyl-6-(phenylsulfonyl)-7-(4-methylphenyl)pyrazolo[1,5-a]pyrimidine (5e) was found to have an excellent analgesic activity in comparison with indomethacin as a reference drug, while the highest anti-inflammatory effect was observed in the case of 2-(4-bromophenyl)-6-(phenylsulfonyl)-5-(4-methylphenyl)pyrazolo[1,5-a]pyrimidine (5d). From the structure-activity relationship (SAR) point of view, the analgesic/anti-inflammatory activity of pyrazolo[1,5-a]pyrimidine derivatives was found to be much higher than triazolo[1,5-a]pyrimidine and pyrimido[1,2-a]benzimidazole derivatives.

Radiation-induced grafting of glycidyl methacrylate onto cotton fabric waste and its modification for anchoring hazardous wastes from their solutions.

Ion exchange adsorbents based on cellulosic fabric wastes carrying sulfonic acid and amine functional groups were synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains with sodium sulfite/H(2)SO(4) and triethylamine, respectively. The conversion of epoxy groups into the functional groups was investigated. Factors affecting on grafting process such as radiation dose, monomer concentration and solvent were studied. The synthesized adsorbent and its applications in the removal of different types of hazardous pollutants e.g. acidic dye, cobalt, dichromate and phenols from aqueous solution were also studied.

Single Step Synthesis of New Fused Pyrimidine Derivatives and Their Evaluation as Potent Aurora-A Kinase Inhibitors

A simple, facile, efficient and one pot three-component procedure for the synthesis of pyrazolo[1,5-a]pyrimidines, triazolo[1,5-a]pyrimidines and pyrimido[1,2-a]benzimidazoles ring systems incorporating phenylsulfonyl moiety was developed via the reaction of 1-aryl-2-(phenylsulfonyl)ethanone derivatives 1a-d with the appropriate heterocyclic amine and triethyl orthoformate and evaluated as Aurora-A kinase inhibitors. The cytotoxic activity of the newly synthesized compounds against HST116 colon tumor cell line was investigated. 2,7-Diphenyl-6-(phenylsulfonyl)pyrazolo[1,5-a]pyrimidine (4b) and its p-methoxy analogue 4c were found to be equipotent to Doxorubicin as a reference drug. Molecular modeling study was carried out in order to rationalize the in vitro anti-tumor results.

Recent advances in the therapeutic applications of pyrazolines.

Introduction: Pyrazolines are well-known and important nitrogen-containing five-membered ring heterocyclic compounds. Various methods have been worked out for their synthesis. Several pyrazoline derivatives have been found to possess diverse biological properties, which has stimulated research activity in this field. Areas covered: The present review sheds light on the recent therapeutic patent literature (2000 – 2011) describing the applications of pyrazolines and their derivatives on selected activities. Many of the therapeutic applications of pyrazoline derivatives have been discussed, either in the patent or in the general literature areas in this review. In addition to selected biological data, a wide range of pharmaceutical applications and pharmaceutical compositions are also summarized. Expert opinion: Pyrazoline derivatives have numerous prominent pharmacological effects, such as antimicrobial (antibacterial, antifungal, antiamoebic, antimycobacterial), anti-inflammatory, analgesic, antidepressant and anticancer. Further pharmacological effects include cannabinoid CB1 receptor antagonists, antiepileptic, antitrypanosomal, antiviral activity, MAO-inhibitory, antinociceptive activity, insecticidal, hypotensive, nitric oxide synthase inhibitor, antioxidant, steroidal and antidiabetic. Lastly, they also effect ACAT inhibition, urotensin II and somatostatin-5 receptors, TGF-β signal transduction inhibitors and neurocytotoxicity inhibitors activities. Many new pyrazoline derivatives have been synthesized and patented, but there are still new aspects to explore and work on.

Synthesis and antimicrobial evaluation of new thiophene and 1,3,4-thiadiazole derivatives

A Facile route to some new thiophene derivatives via the reaction of 3-mercapto-2-(1-methylbenzimidazole-2-carbonyl)-3-phenylaminopropenal (3) with 1-aryl-2-bromoethanones, chloroacetonitrile and ethyl bromoacetate is reported. Reaction of 3 with hydrazonoyl halides afforded 1,3,4-thiadiazole derivatives incorporating a benzimidazole moiety. Antimicrobial and antifungal activities of selected examples of the new products were evaluated.

Synthesis and antimicrobial evaluation of novel pyrazolo〔1,5-a〕pyrimidine triazolo〔1,5-a〕pyrimidine and Pyrimido〔1,2-a〕benzimidazole derivatives

The applicability and synthetic potency of E-1 -(1-methylbenzimidazol-2-yl)-3 -N,N-dimethylaminoprop-2-enone towards some nitrogen nucleophiles was investigated as a convenient route for the synthesis of some novel aminopyrimidine, pyrazolo[1 ,5-a]pyrimidine, triazolo[1 ,5-a]pyrimidine, pyrimido[1,2-a]benzimidazole, and pyrido[2,3-d]pyrimidine derivatives. Some of the newly synthesized compounds were tested in vitro for their antibacterial and antifungal activities, and showed promising results.

Synthesis and Structure-activity Relationship Studies of Pyrazole-based Heterocycles as Antitumor Agents

Several 4‐cyano‐1,5‐diphenylpyrazoles attached to different heterocyclic ring systems at position 3 were synthesized starting from ethyl 4‐cyano‐1,5‐diphenyl‐1H‐pyrazole‐3‐carboxylate 1. The newly synthesized compounds were tested in vivo for their anti‐estrogenic effects and evaluated in vitro for their cytotoxic properties against estrogen‐dependent tumors. 3‐(5‐Mercapto‐1,3,4‐oxadiazole‐2‐yl)‐1,5‐diphenyl‐1H‐pyrazole‐4‐carbonitrile 13 revealed the highest cytotoxic activity with a GI50 value equal to 40 nM against the IGROVI ovarian tumor cell line. It also showed an anti‐estrogen activity 1.6 more effective than the reference drug, in addition to a high tolerable dose. 3‐(5‐(Methylthio)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1,5‐diphenyl‐1H‐pyrazole‐4‐carbonitrile 7 was found to have the highest anti‐estrogenic activity, while 1,5‐diphenyl‐3‐[5‐(phenylamino)‐1,3,4‐thiadiazol‐2‐yl]‐1H‐pyrazole‐4‐carbonitrile 11 showed the lowest activity. The oral LD50 values revealed that most of the tested compounds are relatively nontoxic.

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF NEW PYRAZOLE, THIOPHENE, THIAZOLE AND 1,3,4-THIADIAZOLE DERIVATIVES INCORPORATING PYRIMIDINE RING

The utility of 3-oxo-N-(pyrimidin-2-yl)butanamide (1) in the synthesis of some new pyrazole, thiophene, thiazole, and 1,3,4-thiadiazole derivatives pendant to a pyrimidine ring is reported. Antimicrobial evaluation of some selected examples from the synthesized products was carried out and showed moderate activity.