Method for synthesizing (Z)-2-(alpha-methoxyimino)furanylacetic acid ammonium

The invention belongs to the technical field of medical intermediate preparation, and particularly relates to a method for synthesizing (Z)-2-(alpha-methoxyimino)furanylacetic acid ammonium. The method comprises the following steps that 1, 2-oxo-2-furanylacetic acid and heavy metal salt are dissolved in water, an aqueous methoxyamine solution or aqueous methoxyamine salt solution is added at the temperature of 0 DEG C-10 DEG C, and the pH is regulated to 2.5-3.5; 2, heat preservation is performed for 2-7 h at the temperature of 5 DEG C-10 DEG C, and a 2-(alpha-methoxyimino)furanylacetic acid solution is obtained; 3, the pH of the 2-(alpha-methoxyimino)furanylacetic acid solution is regulated to 0.1-1.5 by adopting inorganic acid, the temperature is controlled at 15 DEG C-25 DEG C, extraction is performed through organic solvent, and organic phases are combined; 4, ammonia gas or liquid ammonia is introduced into the organic phases at the temperature of 0 DEG C-10 DEG C, the pH is regulated to 6.5-7.5, heat preservation is performed for 0.5-1.5 h to obtain a crude product, and after decoloration, concentration and crystallization are performed, the product is obtained. The method is high in yield and good in product quality.