the invention relates to a method for synthesizing an intermediate of apixaban comprising reacting a compound of formula i with 5 - chloro - valeryl chloride in the presence of inorganic base in an inert solvent to obtain a compound of formula ii , with the reaction formula of , wherein r is selected from nitro group and the group . the method is mild in reaction condition , simple in operation , easy in purification , inexpensive in production cost , environmental - friendly , and suitable for industrial production .