PURPOSE: To obtain in high yield the titled substance useful as a precursor raw material for a sweetener without using free ammonia and causing problems of acid treatment and coloring, by reacting a prussic acid compound and an ammonium slat with phenylacetaldehyde under a specific temperature condition and further carrying out the reaction under specific rise in temperature.
CONSTITUTION: A prussic acid compound and one or more ammonium salts(preferably ammonium bicarbonate is used) selected from ammonium bicarbonate and ammonium carbamate in an aqueous medium are previously fed to a reactor, they are reacted with phenylacetaldehyde at 0W60°C, preferably 10W50°C while adding continuously phenylacetaldehyde and after the addition is over, the reaction is carried out by raising the reaction temeprature to ≤120°C, preferably 70W100°C, to give the aimed compound. The amount of the prussic acid is preferably 1.0W1.2mol based on phenylacetaldehyde and the amount of ammonium bicarbonate is preferably 1.0W1.6mol.
OSAI YOSHIO
MIYASHITA YASUO
SHIMIZUI TSUNEHIKO
