| 摘要 |
The title compd. (I) and its pharmaceutically active salts comprise (1) desulfuration of 1st beta-lactam of formula (II) to (III), and (2) halogenation of (III) to (IV), and (3) cyclization of (IV). R is H, 1-hydroxyalkyl substd. with C1-2 1-hydroxy alkyl or hydroxy- protection gp.; R1 is C1-4 alkyl-G, C1-4 alkyl-G1 (G=H, C1-5 alkoxy, C3-7 2(alkoxy)ethoxy; G1=C2-6 N-alkanoyl); R2 is H, ester or carboxylic acid protection gp. (hydrolysis in an organism); X is O or S; R4 is C1-7 alkyl, C1-4 alkoxy; R5 is Cl, Br or I; i is 0 or 1.
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