PURPOSE: To obtain the titled compound useful as an intermediate for preparing dye, etc. without causing problems in terms of environmental pollution resulting from the use of an organic solvent, by halogenating a p-aminoazobenzene with an aqueous solution of a hydrohalogenic acid in an aqueous medium in the presence of hydrogen peroxide.

CONSTITUTION: As a p-aminobenzene shown by the formula I (benzene ring A is lower alkyl, lower alkoxy, nitro, lower alkoxycarbonyl, or halogen) is added to an aqueous solution (preferably 1W10wt% concentration) of a hydrohalogenic acid shown by the formula H-X (X is Cl, Br or I) and dissolved or suspended, the aqueous soution is reacted with hydrogen peroxide at 30W90°C, to give a halogenated p-aminobenzene shown by the formula II or formula III. Since an organic solvent is not used, a raw material compound can be directly used without drying a wet filtered mass in a previous process.