Efficient reductive acylation of 3-nitroindoles

3-Nitroindoles are catalytically reduced by hydrogen on palladium/carbon to furnish the relatively unstable aminoindoles, which in the presence of carboxylic acid anhydrides afford good to excellent yields of the corresponding N-acylaminoindoles. 2-Nitroindoles give lower yields of N-acylated 2-aminoindoles.