Novel synthesis method of bromfenac sodium

The invention discloses a novel synthesis method of bromfenac sodium, which belongs to the technical field of drug synthesis, and is characterized in that the preparation method comprises the following steps of taking o-aminophenylacetic acid as an initial raw material, and obtaining an intermediate I through acylation reaction, performing sulfonation reaction on the intermediate I to obtain an intermediate II, carrying out substitution reaction on the intermediate II and p-bromobenzoyl chloride to obtain an intermediate III, hydrolyzing the intermediate III to obtain bromfenac, and reacting bromfenac with sodium hydroxide to obtain the final product bromfenac sodium. The method has the beneficial effects that the generation of impurities containing indole rings caused by a synthesis method in the prior art is avoided; the problem that in the prior art, phosphoric acid or glacial acetic acid is used for producing acid salt, so that the pH value of a final finished product exceeds the standard is solved, the q