Eco-Friendly Synthesis of Some Thiosemicarbazones and Their Applications as Intermediates for 5-Arylazothiazole Disperse Dyes

Abstract

The solid-solid reactions of thiosemicarbazide with 4-formylantipyrine, 2-acetylpyrrole and camphor were performed to afford the thiosemicarbazones 1–3 which underwent hetero-cyclization with phenacyl bromide to furnish the corresponding thiazole derivatives 4–6. The yields of the reactions are quantitative in all cases and the products do not require further purification. A series of 5-arylazo-2-(substituted ylidene-hydrazinyl)-thiazole dyes 7–9 was then prepared by diazo coupling of thiazole derivatives 4–6 with several diazonium chlorides. The synthesized dyes were applied as disperse dyes for dyeing polyester fabric. The dyed fabrics exhibit good washing, perspiration, sublimation and light fastness properties, with little variation in their moderate to good rubbing fastness.

Keywords

• solid-solid reactions
• thiosemicarbazones
• phenacyl bromide
• 5-arylazothiazoles
• disperse dyes
• fastness properties.