PURPOSE: To obtain the titled compound with simple process in high yield, by the catalytic vapor-phase oxidation of p-cresol with an O2-containing gas in the presence of a catalyst containing V, an element selected from K, Rb, Cs and Tl and an element selected from copper, silver, P, Sb, Bi, etc.
CONSTITUTION: p-Hydroxybenzaldehyde is produced from p-cresol by catalytic vapor-phase oxidation in the presence of an oxide catalyst containing (A) vanadium and (B) at least one element selected from potassium, rubidium, cesium and thallium or, further, (C) at least one element selected from copper, silver, phosphorus, antimony, bismuth, tin, lead, manganese, molybdenum and tungsten. The atomic ratios of the catalyst elements excluding oxygen are preferably within the range of formula. The process can be carried out extremely advantageously since it does not necessitate auxiliary materials and the amount of waste water, etc., is remarkably decreased.
SAITO NOBORU
TAKATSU KAZUHIRO
