PURPOSE: To obtain the titled compound in high yield, by reacting an aqueous slurry solution of aniline sulfate with nitrogen oxide while controlling the feed rates of both to give the concentration of the aniline sulfate in the aqueous medium at a specific standard or below always.
CONSTITUTION: Aniline sulfate is reacted with a mixture of nitrogen oxides, e.g. NO, NO2 or N2O3, in an aqueous medium to prepare benzenediazonium sulfate. In the process, the feed rates of the raw materials are controlled to give the concentration of the aniline sulfate in the reaction medium of 8wt% or below always, and the diazotation reaction is carried out substantially in the absence of the aniline sulfate slurry in the reaction medium to give the aimed compound. The aniline sulfate fed to the reaction system is converted into the aimed soluble compound in the aqueous medium without accumulating therein. Thus, the diazotation proceeds smoothly due to no deposition of a solid. The diazotation reaction temperature is -10W+10°C, preferably -5W+3°C.
MURATA TETSUO
MORI YOSHIHIDE
