催化氧化法合成对叔丁基苯甲酸

以对叔丁基甲苯(PTBT)为原料,醋酸钴做催化剂,醋酸为溶剂,研究了常压条件下合成对叔丁基苯甲酸(PTBA)的速率常数和反应级数。确定了PTBT的反应级数(n=1),速率常数(k=4 6×10-3min-1)。在常压条件下反应8h,PTBA的收率达到89%。在加压条件下反应0 5h,收率95%。同时研究了无醋酸溶剂的PTBT氧化反应,收率65 4%。

Synthesis of p-tert-Butylbenzoic Acid by Catalytic Oxidation

Liquid phase oxidation of p tert butyltoluene (PTBT) by molecular oxygen in acetic acid medium containing cobalt acetate catalyst and sodium bromide was investigated with a view to developing an industrial process for the production of p tert butylbenzoic acid (PTBA).Under atmospheric pressure,oxidation of PTBT was studied kinetically at 90 ℃.It was found that the oxidation is a first order reaction with regard to substrate concentration and the rate constant (k) of oxidizing PTBT to PTBA was calculated (46×10-3 min-1).89% yield of PTBA was achieved under normal pressure for 8 h.The oxidation reaction of PTBT under high pressure (06 MPa) was also studied,and PTBT was oxidized to PTBA in good yield (95%) for 05 h.The process of oxidizing PTBT to PTBA without acetic acid was investigated,and 654% yield of PTBA was realized at 130 ℃.