Synthesis of cephalosporins with substituted thiadiazoles directly attached to the C3-position. I. Synthesis of 3-(5-substituted-1,3,4-thiadiazol-2-yl)ceph-3-em derivatives.
作者:TOHRU SUGAWARA、HIROTOMO MASUYA、TAISUKE MATSUO、TAKUICHI MIKI
DOI:10.1248/cpb.28.2116
日期:——
3-(5-Substituted-1, 3, 4-thiadiazol-2-yl) ceph-3-em derivatives were prepared by oxidative ring closure with 2, 3-dichloro-5, 6-dicyanobenzoquinone directly or after acetylation of 3-thiocarbonylhydrazones, which were obtained from the reaction of 3-formylceph-3-ems and thiocarbonylhydrazines. The antibacterial activity of 7-thienylacetamido-3-(5-substituted-1, 3, 4-thiadiazol-2-yl) ceph-3-em derivatives (4) against gram-positive organisms was similar to that of cephalothin (CET), while the activity against gram-negative organisms was superior to that of CET. A similar oxidative ring closure reaction with other thiocarbonylhydrazones is also discussed.
通过氧化环合反应,以2,3-二氯-5,6-二氰基苯醌直接或先经乙酰化3-硫羰基腙制得了3-(5-取代-1,3,4-噻二唑-2-基)头孢-3-烯衍生物。这些3-硫羰基腙是从3-醛基头孢-3-烯和硫羰基酰肼反应得到的。7-噻吩基乙酰胺基-3-(5-取代-1,3,4-噻二唑-2-基)头孢-3-烯衍生物(4)对革兰氏阳性菌的抗菌活性与头孢噻吩(CET)相似,而对革兰氏阴性菌的活性则优于CET。还讨论了与其他硫羰基腙的类似氧化环合反应。