Antimicrobial and Dyeing Properties of Reactive Dyes with Thiazolidinon-4-one Nucleus

Four imines, the condensation products of 2,4-dioxo-4-phenylbutanal with four primary amines, were condensed with mercapto acetic acid to obtain thiazolidinon-4-ones which on subsequent condensation with vanillin and isatin separately yielded eight thiazolidin-4-one derivatives. The chemical structures of the synthesized compounds were elucidated by elemental analysis, molecular weight determination, IR and 1H and 13C NMR spectral measurements. Antibacterial and antifungal properties were studied in vitro against two bacteria and two fungi. The dyeing potential of synthesized reactive dyes was investigated with regard to silk, wool, cotton, and polyester fabrics under hot and cold dyeing conditions. 1. Introduction A small heterocyclic ring containing nitrogen and sulphur has been under investigation for pretty long time owing to their potential biological features. Among these heterocyclics, thiazolidinones having thiazol nucleus have been reported to display wide spectrum ofimportant biological activities leading to their medicinal usage such as anticancer [1], antitubercular [2], anti-HIV [3], analgesic [4], anti-inflammatory [4], ulcerogenic [5], sedative [6], antiviral [7], CNS depressant [7], hypnotic [8], antithyroidal [9], antibacterial [10, 11], and antifungal [12, 13]. Besides the pivotal role of thiazolidinones in the field of medicinal science, their many derivatives, exhibiting herbicidal [14], pesticidal [15], and insecticidal [15] properties, have significant role in agriculture. The dyeing [16–18] and ligation [19] properties of thiazolidinones have also been reported. Reactive dyes believed to form homopolar bonds with textile substrates [16, 17] with special finishing capabilities are currently an area of active research. The synthesized thiazolidinone derivatives exhibiting antimicrobial properties and possessing several auxochromic and chromophoric groups reactive with synthetic (cellulose) and natural (protein) fabrics tempted us to evaluate their dyeing potentials with silk, wool, cotton, and polyester fabrics with simultaneous antimicrobial finishing of the textiles. 2. Results and Discussion The synthesis of compounds 9a–h is based on the synthetic routes shown in Scheme 1. Commercially available Benzoyl acetone (1) was oxidized into its glyoxal, 2,4-dioxo-4-phenylbutanal (2), by using selenium dioxide in ethanol. Then, the reaction of glyoxal (2) with substituted anilines such as p-NO2, p-OH, p-OCH3, and p-N(CH3)2 in dry ethanol yielded 3-oxo-3-phenylpropanal azomethines (4) which on cyclocondensation with thioglycolic acid in