A process of reacting a nitroaniline compound of formula (2): with an acid anhydride or acid halide is carried out in the presence of an alkali metal compound or an alkaline earth metal compound to produce an acylnitroaniline derivative. The process further includes the step of reacting the resulting product with a compound of formula (5); R2—Y to produce an N-acylnitroaniline derivative of formula (1): The N-acylnitroaniline derivative of formula (1) is a useful intermediate for the production of pharmaceuticals.