Pyridazinone drug intermediates succinic anhydride synthesis method, comprising the following steps: equipped with a stirrer, a reflux condenser, a reaction vessel was added 0.6 1mol 1-carboxyl-propionamide solution(2), 1.3-1.5mol 2-bromo-phenylacetic acid solution(3), 300ml nitromethane solution, 0.61mol cuprous chloride solution, controlling the stirring speed at 130-160rpm, the solution temperature was raise to 70-75 C, refluxed for 3-5h, the temperature of the solution was reduced to 10-13'C, the precipitated solid was suction filtered, washed with salt solution, washed with toluene solution, recrystallized from ethylenediamine solution, got crystals of succinic anhydride.
