A Convenient Ultrasound-Promoted Synthesis of Some New Thiazole Derivatives Bearing a Coumarin Nucleus and Their Cytotoxic Activity

Abstract

Successful implementation of ultrasound irradiation for the rapid synthesis of a novel series of 3-[1-(4-substituted-5-(aryldiazenyl)thiazol-2-yl)hydrazono)ethyl]-2<em>H</em>-chromen-2-ones<strong> 5a</strong>–<strong>h</strong>, <em>via</em> reactions of 2-(1-(2-oxo-2<em>H</em>-chromen-3-yl)ethylidene) thiosemicarbazide (<strong>2</strong>) and the hydrazonoyl halides <strong>3</strong>(<strong>4</strong>), was demonstrated<strong>.</strong> Also, a new series of 5-arylidene-2-(2-(1-(2-oxo-2<em>H</em>-chromen-3-yl)ethylidene)hydrazinyl)thiazol-4(5<em>H</em>)-ones <strong>10a</strong>–<strong>d</strong> were synthesized from reaction of <strong>2</strong> with chloroacetic acid and different aldehydes. Moreover, reaction of 2-cyano-<em>N'</em>-(1-(2-oxo-2<em>H</em>-chromen-3-yl)ethylidene)-acetohydrazide (<strong>12</strong>) with substituted benzaldehydes gave the respective arylidene derivatives <strong>13a</strong>–<strong>c</strong> under the conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data. Also, the cytototoxic activities of the thiazole derivative <strong>5a</strong> was evaluated against HaCaT cells (human keratinocytes). It was found that compound <strong>5a</strong> possess potent cytotoxic activity.

Keywords

• thiosemicarbazides
• thiazoles
• hydrazonoyl halides
• ultra-sound irradiation
• cytotoxic activity