Ultrasound-promoted tosylation of oligo(ethylene glycols)

A series of oligo(ethylene glycols) was efficiently tosylated by ultrasound procedure within dichloromethane in the presence of triethylamine. Results show that sonochemical synthesis of oligo(ethylene glycol) ditosylates has a double advantage since it does not use catalysts and it drastically reduces the reaction time. This straightforward method represents an eco-friendly alternative to the traditional tosylation by pyridine synthesis.