| 摘要 |
NEW MATERIAL:A compound expressed by formula I [R1 is COOH or COOM (M is an alkali metal, etc.), etc.; R2 is formula II or -SR3 (R3 is a 5- or 6- membered ring, having 1-4 hetero-atoms, and optionally substituted by a lower alkyl group); n is 1 or 2] and a salt thereof. EXAMPLE:The syn-isomer of 7beta-{2-( 2- aminothiazol -4- yl )-2-[(imidazol-4-yl)methoxyimino]acetamido}-3-(1-pyridinium)methyl-3-c ephem-4-carboxylate. USE:An antimicrobial agent. PROCESS:A compound expressed by formula III (X is halogen; R4 is a protecting group of the carboxylic acid) is acylated with a compound expressed by formula IV(R5 and R6 are H, formyl, etc.) to give a compound expressed by formula V, which is then reacted with pyridine or a compound expressed by the formula HS-R3 to afford an intermediate sulfoxide expressed by formula VI. The resultant intermediate sulfoxide expressed by formula VI is then converted into a sulfide derivative. The protecting groups are then removed to afford the compound expressed by formula I . |
