| 摘要 |
PURPOSE:To obtain hydroxy benzoic acid useful as a raw material for a pharmaceutical, an agrochemical, an antiseptic, a perfumery, a dye and other chemicals in high efficiency in a short process through direct hydroxylation by reacting benzoic acid with oxygen and hydrogen in the presence of a noble metal catalyst. CONSTITUTION:o-, m-and p-Hydroxy benzoic acid are obtained by reacting benzoic acid with oxygen and hydrogen in a solvent (e.g. water) in the presence of a catalyst at a temperature from room temperature to 200 deg.C under a pressure from atmospheric pressure to 200kg/cm<2>. As the catalyst of this reaction, a noble metal catalyst supporting a noble metal of the group VIII of the periodic table on a carrier, e.g. a catalyst supporting platinum on zirconia or a modified noble metal catalyst supporting a noble metal of the group VIII of the periodic table and an oxide of at least one kind of base metal selected from the groups IIIa, IVa, Va, VIa, VIIa, IIb, IVb and Vb of a periodic table on a carrier, e.g. a catalyst supporting platinum and vanadium oxide on zirconia. Further, a vanadium compound is preferably added to the reaction system as a promotor. |
