Novel preparation method of pranoprofen

The invention discloses a novel preparation method of pranoprofen. The novel preparation method of the pranoprofen has the advantages of being high in yield, having less impurities, and being safe andenvironmentally friendly. The novel preparation method of the pranoprofen comprises the following steps that step 1, 5H-[1]-benzopyran[2,3-b]pyridine and propionyl chloride are directly acylated; step 2, bromination is carried out; step 3, potassium tert-butoxide or sodium tert-butoxide is used for hydrolysis, and finally, rearrangement is carried out to obtain the pranoprofen. 本发明公开了一种新的普拉洛芬的制备方法，具有收率高，杂质少，安全，环保的优点，包括以下步骤：通过使用5H-[1]-苯并吡喃[2,3-b]吡啶和丙酰氯直接酰基化，然后进行溴代，第三步使用叔丁醇钾或叔丁醇钠水解，最后重排得到普拉洛芬：