D-phenylglycine methyl ester is an important intermediate in the synthesis of cefaclor and ampicillin, which are semi-synthetic second-generation cephalosporins with similar antibacterial spectrum and antibacterial activity to cefazolin, and are mainly used for the treatment of otitis media , lower respiratory tract infection, urinary tract infection, skin and skin tissue infection, can inhibit all Haemophilus influenzae Chemicalbook, including strains resistant to ampicillin. Although the synthesis patent report process is simple, the final product is D-phenylglycine methyl ester hydrochloride. The synthesis of cefuroxime and ampicillin requires desalination, which brings cumbersome processes to the subsequent synthesis, so free D-phenylglycine can be obtained at low cost Methyl ester and has commercial value.