Catalyst-free synthesis of new hydrazino thiazole derivatives in water under ultrasonication and evaluation of their antioxidant activity

An active approach for the preparation of a series of novel 3-[2ʹ-(4ʹ-aryl-1,3-thiazol-2ʹ-yl) hydrazono]indoline-2-one derivatives (4) has been executed by a one-pot multicomponent reaction of differently substituted isatins, hydrazinecarbothioamide and aracyl bromides under catalyst-free ultrasonication. This organic conversion occurs efficiently in an aqueous medium, illustrating a massive functional group tolerance. The method is green and the products are obtained in excellent yield in very short durations. On top of this, the reaction process does not demand for chromatographic purification and this procedure has the potency for extensive utilisation in drug companies. The test compounds 4i and 6 revealed extremely good antioxidant behaviour with IC₅₀ values of 5.02 and 8.54 μg/mL respectively. Additionally, In-silico ADME and bioavailability radar study suggests that the compounds 4i and 6 may be utilized as oral drugs and in the intravenous therapy.