Chemical modification of sulfazecin. Synthesis of 4-methoxycarbonyl-2-azetidinone-1-sulfonic acid derivatives.
作者:SHOJI KISHIMOTO、MICHIYUKI SENDAI、MITSUMI TOMIMOTO、SHOHEI HASHIGUCHI、TAISUKE MATSUO、MICHIHIKO OCHIAI
DOI:10.1248/cpb.32.2646
日期:——
In the course of the chemical modification of sulfazecin, 3-[2-(2-aminothiazol-4-yl)-(Z)-2-(substituted oxyimino) acetamido]-4-methoxycarbonyl-2-azetidinone-1-sulfonic acids were synthesized starting from cis-1-(2, 4-dimethoxybenzyl)-4-methoxycarbonyl-3-phthalimido-2-azetidinone (2). These new 4-substituted derivatives showed more potent antimicrobial activities against gram-negative bacteria than did the corresponding 4-unsubstituted compounds, and the derivatives having 3, 4-cis stereochemistry were more active than the trans isomers, especially against P. aeruginosa and some β-lactamase-producing bacteria. The reported procedure for the cycloaddition reaction used to prepare 2 was investigated in detail ; by the use of a 20% excess of triethylamine, 2 was easily obtained in the yield of 72% as colorless crystals. A possible intermediate of β-lactam formation in this cycloaddition reaction, an acyl iminium salt (6), was isolated as crystals and converted into β-lactams by treatment with 1, 8-diazabicyclo [5. 4. 0]-7-undecene.
在磺扎西丁的化学修饰过程中,从顺式-1-(2,4-二甲氧基苄基)-4-甲氧羰基-3-酞酰亚胺基-2-氮杂环丁酮(2)出发,合成了3-[2-(2-氨基噻唑-4-基)-(Z)-2-(取代氧亚胺基)乙酰胺基]-4-甲氧羰基-2-氮杂环丁酮-1-磺酸。这些新的4-取代衍生物对革兰氏阴性菌的抗菌活性比相应的4-未取代化合物更强,其中具有3,4-顺式立体化学结构的衍生物比反式异构体更活跃,尤其对铜绿假单胞菌和一些产生β-内酰胺酶的细菌更为有效。研究了用于制备2的环加成反应的报道程序;通过使用20%过量的三乙胺,可以很容易地以72%的产率得到无色晶体2。在这种环加成反应中形成β-内酰胺的可能中间体——酰基亚胺盐(6)被分离为晶体,并通过与1,8-二氮杂双环[5.4.0]-7-十一碳烯处理转化为β-内酰胺。