A Highly Efficient One-Pot Synthesis and Antibacterial Activity of Unexpected 2-(2-hydroxyphenyl)-4-oxothiazolidin-3-yl)alkyl/phenylthiazolidin-4-one Derivatives and Their Reaction with Aromatic Aldehydes

Unexpected 2-(2-hydroxyphenyl)-3-(2-(2-hydroxyphenyl)-4-oxothiazolidin-3-yl)alkyl(phenyl)thiazolidin-4-one derivatives (4a-d) were synthesized via the reaction of 3-acetyl chromene with hydrazine hydrate, ethylene diamine, 1,6-diaminohexane, or p-phenylene diamine to afford the corresponding Schiff bases (3a-d), which in turn reacted with thioglycolic acid in the presence of anhydrous ZnCl2. Additionally, compounds 4a-d were prepared in a one-pot reaction involving 3-acetylcumarin, diamine, and thioglycolic acid with ZnCl2. The 5-arylidene derivatives (6a-l) were prepared by reacting 4a-d with aromatic aldehydes (5a-c). The structure of the synthesized compounds was confirmed using elemental analysis, IR, 1H-NMR, and 13C-NMR. This study provides insights into the efficiency of the synthetic process and explores the antibacterial activity of the resulting compounds.