Ultrasound-promoted one-pot five-components synthesis of biologically active novel bis((6-alkyl or phenyl-2-phenylpyrimidine-4-yl) oxy) alkane or methyl benzene derivatives.

We have described a synthesis of novel five-component reaction (5-CR) of bis((6-alkyl or phenyl-2-phenylpyrimidine-4-yl) oxy) alkane or methyl benzene derivatives under ultrasound irradiation. A useful ultrasound effect was observed and title products were obtained with high yields after 25-40 min sonication. Structural confirmation and characterization of the products based on the analytical, chemical, and spectral analysis. The results show obviously, that to reach a high efficiency of ultrasonic systems in synthetic chemical processes. Our procedure compared to the conventional heating method has the benefit of higher reaction yields and shorter reaction times. The in vitro antibacterial tests show that some of the target compounds have promising activities. Structure-activity relationships (SAR) were established for the substitutions on the pyrimidine rings and related length of linear chain linker.

Facile regioselective synthesis of novel bis-thiazole derivatives and their antimicrobial activity.

The design and synthesis of several new bis-thiazoles 4a-h serving as bis-drugs in comparison with mono-heterocyclic analogs are described. These bis-drugs present superior medicinal and pharmacological activities against both gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive (Micrococcus luteus and Bacillus subtilis) bacteria, which are in general more sensitive to compounds with higher hydrophobicity. Compounds with higher hydrophobicity (4d and 4h) exhibited some activity against the gram-negative bacteria.

Facile regioselective synthesis of novel bioactive thiazolyl-pyrazoline derivatives via a three-component reaction and their antimicrobial activity.

A series of novel 2-(3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles have been prepared by a three-component cyclo-condensation of various chalcones, thiosemicarbazide and phenacyl bromide. The easy work-up of the products, rapid reaction, and mild conditions are notable features of this protocol. The reaction was efficiently catalyzed in one-pot by a few drops of HCl in EtOH under reflux conditions providing the title compounds in moderate to high yields. The antibacterial activity of the selected products was examined. Some products exhibit promising activities.