Rapid reduction of heteroaromatic nitro groups using catalytic transfer hydrogenation with microwave heating

A method for the rapid, safe reduction of heteroaromatic and aromatic nitro groups to amines is described using catalytic transfer hydrogenation under microwave heating conditions. Commonly available Pd/C or Pt/C catalyst is extremely effective with 1,4-cyclohexadiene as the hydrogen transfer source. In the case of substrates containing potentially labile aromatic halogens, Pt/C is effective and results in little or no dehalogenation. In general, the reactions are complete within 5 min at 120 °C.

Heteroaromatic and aromatic nitro groups are reduced to amines using Pd/C or Pt/C and 1,4-cyclohexadiene. The reaction is heated at 120 °C using microwave irradiation and the reduction is complete within 5 min.