Ultrasonic promoted catalyst-free N-formylation of amines in neutral ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate

A catalyst-free, simple and efficient protocol for N-formylation of alkyl, aryl, and heteroaryl amines with formic acid under ultrasonic irradiation at room temperature using 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim]BF4 as a neutral medium is described.