Preparation method of isopropyl 2-(3-nitrobenzylidene)acetoacetate

The invention provides a preparation method of isopropyl 2-(3-nitrobenzylidene)acetoacetate, which comprises the following steps: carrying out condensation reaction on 3-nitrobenzaldehyde and isopropyl acetoacetate as initial raw materials by using an organic solvent as a solvent in the presence of catalysts acetic acid and piperidine for 2-8 hours; after carrying out vacuum concentration on the filtrate at 80 DEG C to 2/3-3/4 by volume, cooling to -5-5 DEG C while stirring to crystallize over night; and filtering, and recrystallizing with isopropanol to finally obtain the isopropyl 2-(3-nitrobenzylidene)acetoacetate. The invention shortens the reaction time; the isopropanol, which has lower toxicity than methylbenzene and can enhance the product yield and purity, is utilized as the reaction solvent; the catalytic rate of the catalysts is very high, the reaction is quicker and more thorough, and thus, the catalysts can enhance the yield; the invention enhances the yield and saves the cost; and since the refinement method of column chromatography separation, the technique is easy to operate, has the advantage of cheap and accessible raw materials, and thus, is suitable for industrial production.