Photoreduction of nitro arenes by formic acid in acetonitrile at room temperature

The formic acid-mediated photoreduction of aromatic nitro compounds in room temperature acetonitrile solutions was investigated. This mild photoreduction can be accomplished in high yield, with wide functional group tolerance and short reaction times (30 min to 1 h), and allows a very clean method for the conversion of nitro arenes to amines. Also, the photoreduction, as a convenient, versatile and general method, applies efficiently to polycyclic and heterocyclic nitro arenes.