Ameen A. Abu-Hashem

Synthesis, Characterization, Antioxidant and Antitumor Evaluation of Some New Thiazolidine and Thiazolidinone Derivatives

2‐(2‐Cyano‐acetylamino)‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxylic acid ethyl ester (2) was utilized as a key intermediate for the synthesis of thiocarbamoyl derivative 3 via its reaction with phenyl isothiocyanate. Treatment of 3 with chloroacetyl chloride afforded thiazolidin‐5‐one 4. Compound 7 reacted with different α‐halo carbonyl compounds to give thiazolidine 8a,b, and thiazolidin‐4‐one derivatives 9. Treatment of 4 with the appropriate aromatic aldehyde and tolyl diazonium chloride afforded the corresponding thiazolidin‐5‐one derivatives 5a,b and 6, respectively. The thiazolidin‐4‐one derivative 10 was obtained via the reaction of compound 2 with 2‐mercaptoacetic acid. Finally, the thiazoline 11 was obtained via the reaction of compound 2 with phenyl isothiocyanate/sulfur. The title compounds were characterized by elemental analyses and spectral data. The quantum mechanical calculations for some compounds were accomplished and subjected for antioxidant and antitumor studies, whereas, some of them exhibited promising activities.

Synthesis and anti-microbial activity of some 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile derivatives.

A new series of 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile such as hydrazide hydrazones 3a-h; ethane-1,2-diaminopyridine 6; phthalimidopyridines 8a,b; hydrazides 10a,b; urea 11a and thiourea 11b were synthesized in a good to excellent yield in step efficient process, using 1-amino-4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1) as a key intermediate. The antibacterial and antifungal activities of the synthesized compounds were evaluated. The obtained data indicated that the majority of the tested compounds exhibited both antibacterial and antifungal activities, particularly compounds 8a and 8b showed a comparable effect to a well known antibacterial and antifungal agents.

Synthesis of new visnagen and khellin furochromone pyrimidine derivatives and their anti-inflammatory and analgesic activity.

6-[(4-Methoxy/4,9-dimethoxy)-7-methylfurochromen-5-ylideneamino]-2-thioxo-2,3-dihydropyrimidin-4-ones 1a,b were prepared by reaction of 6-amino-2-thiouracil with visnagen or khellin, respectively. Reaction of 1a,b with methyl iodide afforded furochromenylideneaminomethylsulfanylpyrimidin-4-ones 2a,b. Compounds 2a,b were reacted with secondary aliphatic amines to give the corresponding furochromen-ylideneamino-2-substituted pyrimidin-4-ones 3a-d. Reaction of 3a-d with phosphorus oxychloride yielded 6-chlorofurochromenylidenepyrimidinamines 4a-d, which were reacted with secondary amines to afford furochromenylideneamino-2,6-disubstituted pyrimidin-4-ones 5a-d. In addition, reaction of 5a-d with 3-chloropentane-2,4-dione gave 3-chloro-furochromenylpyrimidopyrimidines 6a-d. The latter were reacted with piperazine and morpholine to give 1-(furochromenyl)-pyrimidopyrimidine-3,6,8-triylpiperazines or-3,6,8-triylmorpholines 7a-d. The chemical structures of the newly synthesized compound ware characterized by IR, 1H-NMR, 13C-NMR and mass spectral analysis. These compounds were also screened for their analgesic and anti-inflammatory activities. Some of them, particularly 3-7, exhibited promising activities.

Synthesis of Benzofuran Derivatives via Different Methods

Abstract This review presents a systematic and comprehensive survey of the methods of preparation of benzofurans. These compounds are important intermediates for the synthesis of a variety of synthetically useful and novel heterocyclic systems. GRAPHICAL ABSTRACT

An eco-friendly procedure for the efficient synthesis of arylidinemalononitriles and 4,4′-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols) in aqueous media

Abstract Commercially available lithium hydroxide monohydrate (LiOH·H2O) was found to be a novel “dual activation” catalyst for Knoevenagel condensation between malononitrile (1) or 3-methyl 1-phenyl-1H-pyrazol-5-(4H)-one (6) with aromatic aldehydes 2a–e leading to an efficient and easy synthesis of arylidenemalononitriles 3a–d and 4,4′-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols) 7a–c in short times. The reaction of aryl aldehydes with malononitrile afforded excellent yields after 1–6 min in aqueous media at room temperature. In case of 3-methyl-1-phenyl-1H-pyrazol-5-(4H)-one (6) and aromatic aldehydes afforded good yields after 60–75 min at 90°C.

Synthesis, reactions and biological activities of furochromones: A review

Furochromone derivatives are important synthetic targets which showed a myriad of interesting biological activities. Ammi visnaga (Umbelliferae) is the most famous source of these derivatives, which has been used in folk medicine for millennia targeting different ailments. Since the isolation of furochromone derivatives, different synthetic methodologies were developed for their preparation. Despite the recent interesting findings on this class of compounds, the chemical literatures lack a comprehensive summary on the synthetic methodologies and biological activities of furochromone derivatives. This review highlights recent advances in furochromones chemistry by discussing different synthetic procedures developed for the preparation of naturally occurring derivatives as well as other unique derivatives which showed promising biological activities. It also sheds light on the most common reactions of furochromone derivatives and the utilization of these derivatives as the blocks for many biologically active compounds.

Synthesis of new pyrazole, triazole, and thiazolidine-pyrimido [4, 5-b] quinoline derivatives with potential antitumor activity

Abstract2-Hydrazinyltetrahydropyrimido [4, 5-b] quinolin-4(3H)-one (3) was prepared by desulfurization reaction of S- and N-dimethyl derivatives 2 with hydrazine hydrate. Reactions of (3) with malonitrile, carbondisulfide, potassium thiocyanate, phthalic anhydride and aromatic aldehydes afforded 3, 5-di aminopyrazolopyrimido [4, 5-b] quinoline (4), triazolotetrahydropyrimido [4, 5-b] quinoline (5), aminotriazolopyrimido [4, 5-b] quinoline (6), aminophthalimidopyrimido [4, 5-b] quinoline (7) and N-arylidene hydrazinepyrimido [4, 5-b] quinoline 8a–d, respectively. Furthermore, 8a–d reacted with mercaptoacetic acid gave the thiazolidinonepyrimido [4, 5-b] quinoline 9a–d, which afforded the thiazolotriazolopyrimido [4, 5-b] quinolinone 10a–d upon treatment with ethanolic potassium hydroxide. The newly synthesized compounds were characterized by elemental analyses, IR, 1H-NMR, 13C-NMR and mass spectrometer. The investigated compounds were screened for their cytotoxicity. Compounds 4, 6 and 5 exhibited potent antitumor activity.

5-Chloropyrazole-4-carboxaldehydes as synthon in heterocyclic synthesis

This review presents a systematic and comprehensive survey of the method of preparation and the chemical reactivity of 5-chloropyrazole-4-carbaldehyde. These compounds are important intermediates for the synthesis of a variety of otherwise difficult to obtain, synthetically useful, and novel heterocyclic systems.Graphical Abstract

Reactivity of Benzofuran Derivatives

Abstract This review presents a systematic and comprehensive survey of the chemical reactivity of benzofurans. These compounds are important intermediates for the synthesis of a variety of useful and novel heterocyclic systems that are otherwise difficult to obtain synthetically. GRAPHICAL ABSTRACT

Synthesis of novel 1, 2, 4-triazolopyrimidines and their evaluation as antimicrobial agents

Abstract7-aminopyrimidin-5(1H)-one (5) was utilized as a starting material for the preparation of new, Schiff bases (13–19), amides 23, 24, imide 25, as well as thiourea derivatives 30–33 incorporating the triazolopyrimidines nucleus in their molecules. Structural elucidations for the new compounds were based upon compatible microanalytical and spectroscopic measurement. Biological evaluation indicated that compounds 23, 31, 33, 32, and 30 possess promising antimicrobial activities.Graphical Abstract