Ultrasound-assisted synthesis of isatin-type 5′-(4-alkyl/aryl-1H-1,2,3-triazoles) via 1,3-dipolar cycloaddition reactions

Abstract

This short report describes the preparation of twelve isatin derivatives, 5′-(4-alkyl/aryl-1H- 1,2,3-triazoles), using 5-azido-spiro[1,3-dioxolane-2,3′-indol]-2′(1′H)-one in the presence of various alkynes under acidic conditions and ultrasound irradiation. Compared with conventional methods, yields increased to 78-98%, and reaction times decreased to 5 min. Besides time and energy saving, there was no need for purification of the product by column chromatography on silica gel, generating less waste and spent solvent.