A facile and environmentally benign polyethylene glycol 600-mediated method for the synthesis of densely functionalized 2-aminothiophene derivatives under ultrasonication

[摘要] A green and efficient protocol for the synthesis of densely functionalized 2-aminothiophene derivatives is described by the one-pot three-component Gewald reaction from enolizable carbonyl compounds, malononitrile (or ethyl cyanoacetate) and elemental sulfur in polyethylene glycol 600, as an eco-friendly reaction medium, without using any basic compounds under ultrasonic be recovered and reused at least five times without significant loss of its activity. The merits of this protocol are mild reaction conditions, good yields, short reaction time, simple work-up procedure and recyclability of the reaction medium as well as avoiding the use of any basic catalyst at ambient temperature.

[学科分类] 化学（综合）

[关键词] 2-aminothiophenes;gewald reaction;polyethylene glycol (PEG) 600;multicomponent reactions (MCRs);ultrasound irradiation