The compound 8 was synthesized by 4-nitrophenyl-hydrazine and 2- oxo-propionic acid ethyl ester by nucleophilic addition, rearrangement by total yield 67.9%, and the cost was decreased.

• 以对硝基苯肼、丙酮酸乙酯为原料，经亲核加成、环化（2步总收率67.；9%25）合成了化合物8，降低了生产成本。