Sequential one‐pot multicomponent synthesis of bis‐aminothiazols and evaluation of their antibacterial and antioxidant activities.

A series of novel bis‐thiazoles were synthesized through a one‐pot semi‐five‐component reaction of the prepared α‐bisbromo ketones, aldehydes, and thiosemicarbazide in the presence of p‐TsOH under reflux condition. Products were obtained in reasonable yields via an efficient, convenient, and simple setup. The inhibitory activity on bacterial growth of the products was studied against Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive bacterial strains (Micrococcus luteus, Staphylococcus aureus) at different concentrations (25, 50, 100, and 200 μg/mL at 600 nm). Most of the products showed inhibitory activity at the concentration of 200 μg/mL. In addition, bis‐thiazoles showeed high to moderate antioxidant activity using the diphenylpicrylhydrazyl (DPPH) method. Bis‐thiazoles 6i and 6j showed higher antioxidant activity than vitamin C and vitamin E. A series of novel bis‐thiazoles were synthesized through a one‐pot semi‐five component reaction of the prepared α‐bisbromo ketones, aldehydes, and thiosemicarbazide in the presence of p‐TsOH under reflux condition. Most of the products showed good to excellent inhibitory activity against Gram negative and Gram‐positive bacterial strains. The bis‐thiazoles showed high to moderate antioxidant activity using (DPPH) method. [ABSTRACT FROM AUTHOR]