Design, Synthesis, and Biological Evaluation of Some New Thiazole-Based Compounds as Antioxidant and Antimicrobial Agents

Abstract

This work aims to synthesize novel thiazole analogues through a strategic multicomponent reaction connecting ethyl 2-(2-aminothiazol-4-yl)acetate (1). The acetohydrazide derivative 2 is chloroacetylated twice: at the amino and acetohydrazide groups. Reacting the conforming bis-chloroacetamide derivative 3 with two molar values of 2-mercaptobenzothiazole resulted in the equivalent bissulfide compound 4. The base-catalyzed addition of thiazole derivative 1 to phenyl isothiocyanate afforded intermediate 5, which upon subsequent reaction with ethyl bromoacetate yielded the corresponding thiazolyl-thiazolidine derivative 6. The heated chloroacetamide 7 with ammoniumthio cyanate to give thiazolidin-4-one hybrid 9 was condensed with 3 aromatic aldehyde derivatives furnishing the corresponding 5-arylidene-2-imino-4-thiazolidinones 10a–c, also the synthesized compound 7 was treated with two kinds of thiocarbamoyl compounds 11 and 13 to produce thiazolylthiophenes 12 and 14. Comprehensive structural characterization of the novel synthesized analogues was achieved using elemental analysis and characterized using ¹H NMR, ¹³C NMR, FT-IR, and ESI-MS spectroscopy. The designed thiazole-based compounds exhibited broad-spectrum against antioxidant and antimicrobial activities which will facilitate their rational usage in multiple therapeutic applications.