with or without warning to 50 degrees C. Bases nucleophilic enough to displace the triflate include a variety of substituted pyridines and N-methylimidazole. Deprotection then produced a very active series of 1-[7 beta-[(2-amino- 4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo- 1-azabicyclo[4.2.0]oct-2-en-3-yl] quaternary ammonium hydroxide inner salts. These compounds were extremely potent antibacterials
描述了一系列结构独特的1-carba-1-dethiacephems。1-carba-1-dethiacephem核的结构稳定性对于制备该系列的3-季
铵碳
萘啶是至关重要的。已知的对硝基苄基7β-(苯氧基乙酰胺基)-3-[[(三
氟甲基)磺酰基]氧基] -1-carba-1-dethia-3-cephem-4-
羧酸酯既用作季
铵化底物,又用作前体衍
生物,例如烯丙基7β-[[[2- [烯丙基氧基]羰基]
氨基-4-
噻唑基] [(甲氧基亚
氨基)乙酰基]
氨基] -3-[((三
氟甲基)磺酰基]氧] -1-碳-1-1-
硫醇-3 -cephem-4-
羧酸盐。这些烯醇
三氟甲磺酸酯的季
铵化反应可通过溶解在含有碱的
乙腈中或通过溶解在碱中来实现,无论是否警告到50摄氏度。足以取代
三氟甲磺酸酯的亲核碱基包括各种取代的
吡啶和
N-甲基咪唑。然后脱保护产生了一系列非常活跃的1- [7β-[(2-
氨基-4-
噻唑基)(甲氧基亚
氨基)乙酰基]
氨基]