PROCESS FOR PREPARING BETA-LACTAMS HAVING SIDE CHAINS OF AMINOTHIAZOLEACETIC ACID AND 2-{(-[1-(2-AMINO-4-THIAZOLYL)-2-SUBSTITUTED 2-OXOETHYLIDENE]IMINOOXY- )} PROPANIC ACID Russian patent published in 1994 - IPC

FIELD: used as antibacterial agents. SUBSTANCE: beta- lactams having side chains of aminothiazoleacetic acid (iminooxyacetic acid) are prepared by reacting a [(2S-trans)-3-amino-2-methyl-4-oxo-1- azotidinesulfonic acid internal salt with 2-amino-α-[(1-carboxy-1- methylethoxy) imino]-4-thiazolylacetic acid methanesulfonate and 2,5 dioxo-1-pyrrolidinyl ester in the presence of a base. EFFECT: improved properties of the title products.