Process for the manufacture of p-nitro-ω-bromoacetophenone, especially p-nitroacetophenone, was studied as the material for the synthesis of chioramphenicol and an extremely easy and economical industrial process was established. Some observations are described on the relationship between conditions and yield of nitration of ethylbenzene, synthesis of p-nitroacetophenone by the liquid-phase, catalytic oxidation of 1-ethyl-4-nitrobenzene with oxygen at normal pressure, with various catalysts, and its catalyst poisons.