Mohamed S. Behalo

An Efficient One-Pot, Three-Component Synthesis of 5-Hydrazinoalkylidene Rhodanines from 1,2-Diaza-1,3-dienes

A novel three-component synthesis of 5-hydrazinoalkylidene rhodanine derivatives starting from aliphatic primary amines, carbon disulfide, and 1,2-diaza-1,3-dienes is described. The reaction proceeds successfully under both solution and solid-phase conditions.

Synthesis of 3-(phenoxathiin-2-yl)-2-pyrazoline derivatives as new antibacterial and antifungal agents

A new series of 3-(phenoxathiin-2-yl)-5-aryl-2-pyrazoline derivatives were synthesized from the reaction of 1-(phenoxathiin-2-yl)-3-phenyl/(4-chlorophenyl)propenones 1a and 1b with different nitrogen nucleophiles. The titled compounds were investigated for their antibacterial and antifungal activities and were compared with the standard drugs. Most of the synthesized compounds demonstrated potent to weak antimicrobial activity.

An efficient one-pot catalyzed synthesis of 2,5-disubstituted-1,3,4-oxadiazoles and evaluation of their antimicrobial activities

One-pot synthesis of 1,3,4-oxadiazole derivatives was achieved by treatment of 2-((4-(phenoxathiin-2-yl)phthalazin-1-yl)oxy)acetohydrazide with aromatic aldehydes in the presence of cerium(IV) ammonium nitrate in dichloromethane. This facile method was confirmed by the cyclization–oxidation reaction of the corresponding hydrazone by cerium(IV) ammonium nitrate to afford the same 1,3,4-oxadiazoles. Also, the reaction of 2-((4-(phenoxathiin-2-yl)phthalazin-1-yl)oxy)acetohydrazide with aromatic carboxylic acids in the presence of cerium(IV) ammonium nitrate in polyethylene glycol afforded 1,3,4-oxadiazole derivatives. The structural formulae of all products were confirmed and characterized by elemental analyses and spectral data. Most of the synthesized products were evaluated for their antibacterial and antifungal activities and showed potent to weak activity.

Synthesis of novel pyridazine derivatives as potential antimicrobial agents

A series of novel pyridazine derivatives incorporated with triazole, thiazolidine, imidazolidine, oxazine, and quinazoline moieties was synthesized by the reaction of [6-(4-phenoxyphenyl)pyridazin-3-yloxy]acetyl isothiocyanate with variety of nucleophilic reagents. The structures of all products were confirmed and characterized by the elemental analysis and spectroscopic studies (IR, MS, 1H NMR). Also, the products were investigated for their antibacterial and antifungal activities and were compared with the standard drugs. Most of the synthesized compounds demonstrated potent to weak antimicrobial activity. GRAPHICAL ABSTRACT

Efficient synthesis of thieno[2,3-d]pyrimidines and related fused systems

The synthetic potency of readily accessible, ethyl 2-amino-4-methyl-5-(4-nitrophenoxy)thiophene-3-carboxylate (1) as a versatile precursor for the synthesis of novel polyfunctionally substituted thienopyrimidines is reported. The latter derivatives undergo further heterocyclisation to the related polycyclic fused systems via reactions with different reagents.

Cardanol-based green nanovesicles with antioxidant and cytotoxic activities

ABSTRACT This manuscript describes the preparation of green nanovesicles by using cardanol as renewable starting material with embedded minor amounts of phthalazines, a class of heterocyclic bioactive compounds. The nanovesicles were prepared by stirring induced self-assembly in aqueous medium without involvement of any organic solvent. Dynamic light scattering studies and transmission electron microscopy revealed the formation of nanostructure with an average diameter in the range of 227–375 nm and a well defined spherical morphology. Potential antioxidant activity of nanovesicles were evaluated for the first time by 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging assay and bleomycin-dependent DNA damage. Moreover, their cytotoxic effects were also investigated by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay on different tumour cell lines. Unloaded nanovesicles showed moderate antioxidant and antitumoural activity that was further enhanced particularly by embedding the 2-[4-(4-Hydrazinophthalazin-1-yl)-phenyl]-isoindole-1,3-dione compound.

Synthesis of new peptidyl- and glycosylpyrimidine derivatives

A new series of 2-N-(phthalyl- or tosylamino acid)pyrimidines have been synthesised from the coupling of pyrimidine derivatives with phthalyl- or tosylamino acids. Hydrazinolysis of 2-N-phthalyl derivatives afforded unprotected amino acid derivatives. New derivatives of peptidylpyrimidines have been synthesised from the reaction of pyrimidine derivatives with α-amino acids methyl ester hydrochloride viz different routes. Also, new glycosides have been prepared from the reaction of pyrimidine derivatives with α-D-glucopyranosyl bromide. Most of the synthesised compounds showed a significant antimicrobial activity.

Facile three-component synthesis of dithiocarbamate derivatives with potent antimicrobial activity

A one-pot three-component synthesis of 3-oxo-3-(phenoxathiin-2-yl)-1-phenyl/(4-chlorophenyl)propyl alkyl/aryl-dithiocarbamate was achieved from the reaction of 3-phenyl/(4-chlorophenyl)-1-(phenoxathiin-2-yl)propenones, amine and carbon disulfide. The antimicrobial activities of some compounds were also screened against some selected bacteria and fungi.