PURPOSE: To provide readily and quantitatively the subject compound useful as dyestuff intermediates in high purity by hydrogenating a specific aromatic nitro compound and a specific carboxylic acid as a starting material in the presence of a nickel catalyst under a specific pressure.

CONSTITUTION: An aromatic nitro compound of formula I [A is a bridging group; Z is formula II, -CH=CH2- or formula III (Y is a group removable under alkaline conditions); the benzene uncleus I may be further substituted when necessary] amd a lower aliphatic or aromatic mono- or di-carboxylic acid, e.g. acetic acid, and hydrogenated preferably in an aq. solution or aq. organic solvent in the presence of a nickel catalyst or Raney-Ni catalyst deposited on a carrier activated with MgO on diatomaceous earth. The hydrogenation is effected at 30-150°C within a pH range of 4.5-7 under a pressure of 0.1-100 bar for 1-2 hours, thereby to give an objective compound of formula IV containing a fiber-reactive group.