Method for synthesizing cefodizime sodium intermediate 2-mercapto-4-methyl-5-thiazoleacetic acid

The invention relates to a method for synthesizing a pharmaceutical intermediate, in particular to a method for synthesizing a cefodizime sodium intermediate 2-mercapto-4-methyl-5-thiazoleacetic acid.The method comprises the following steps of adding ammonium dithiocarbamate into an alkaline solvent, raising the temperature, dropwise adding 3-chloropropanoate, and conducting heat-preservation stirring; adding activated carbon for decolorization after dissolved clarification, conducting filtering, and conducting decompression distillation on obtained filtrate; washing and filtering solid products after the distillation with water, and conducting vacuum drying on remaining solid products to obtain 2-mercapto-4-methyl-5-thiazoleacetic acid. By means of the method, the product yield is greater than or equal to 60%, the product purity is greater than or equal to 99.5%, the production rate is obviously increased, the production cost is reduced, and the method meets the needs of industrial production. 本发明涉及种医药中间体的合成