Promotor and method for preparing the same

A method for preparing a promotor, wherein the promotor comprises an aniline derivative having the following structure:

• and the method comprises the following steps:
• (a) pouring bromofluorobenzene and isopropylamine into a bottle and slowly adding potassium tert-butoxide to form a mixture;
• (b) heating the mixture obtained in step (a) to reflux, and then filtering the mixture to remove potassium tert-butoxide after cooling to room temperature to obtain a first liquid;
• (c) removing isopropylamine and tert-butanol from the first liquid obtained in step (b) by distillation under reduced pressure to form a second liquid;
• and
• (d) obtaining an organic phase from the second liquid obtained in step (c) by stratification, adding water into the organic phase for extraction and washing until the organic phase is not turbid, drying the organic phase with anhydrous magnesium sulfate and then filtering, removing excess solvent by concentration under reduced pressure, and finally removing excess reactant bromofluorobenzene from the concentrated organic phase by vacuum distillation to obtain the promotor.