The invention belongs to the technical field of
medicine, and relates to a method for easily and efficiently synthesizing n-
butylphthalide. The method particularly comprises the following steps that in the presence of a
copper iodide catalyst, o-cyanobenzaldehyde is reacted with a
Grignard reagent of n-
butyl bromide in
solvent;
hydrochloric acid is added for a reaction after the reaction in the first step is completed, standing layering is conducted, and an organic phase is obtained; the organic phase is washed through an aqueous
hydrochloric acid solution, a
sodium hydroxide aqueous solution is added,
reflux is conducted through heating, standing layering is conducted after
reflux is completed, and an aqueous phase is obtained; pH of the aqueous phase is adjusted to 3-4, a reaction is conducted through heating,
solvent extraction is conducted after the reaction is completed, concentration and
vacuum distillation are conducted on an obtained
oil phase, and a finished product is obtained. According to the method for easily and efficiently synthesizing the n-
butylphthalide, the raw materials are easy to obtain, the yield is high, the cost is low, industrialization is easy, the n-
butylphthalide with the content of any individual
impurity smaller than 0.1 percent can be obtained, and the purity is larger than 99.7 percent.