Study on Synthesis of p-Isopropylbenzoic Acid from βPinene

p-Isopropylbenzoic acid is synthesized from β-pinene,through a three-step sequence of oxidation,ring-opening and dehydrogenation.The overall yield is 29.9 %.The synthesis of the goal is a new approach.Besides,the conditions of each reaction step are studied.The dehydrogenation of dihydrocumic acid has been discussed emphatically.The optimum conditions of(dehydrogenation) are 7.5 % Pd/C as catalyst,p-isopropylmethylbenzene as solvent,refluxing time 2 h.The yield is 89 %.