Mechanistic Investigation of the Degradation of Sulfamic Acid 1,7-Heptanediyl Ester, an Experimental Cytotoxic Agent, in Water and 18Oxygen-Enriched Water
作者:Mehdi Paborji、Wanda N. Waugh、Valentino J. Stella
DOI:10.1002/jps.2600760216
日期:1987.2
studies, the pH-rate profile and buffer studies, and kinetic solvent isotope effect (KSIE) studies were consistent with an SN2 mechanism with an early transition state (reactant-like transition state) where no appreciable bond had developed between the incoming nucleophile, water, and the carbon atom of 1. Although an SN1 mechanism was unlikely, based on the need to postulate the formation of a primary
氨基磺酸1,7-庚二酯的水解降解是在47°C的水中和富含18O的水中进行的。在恒定的离子强度下,在2.5至8.0的各种pH值下,也研究了1的降解。 0.15 M)和温度(25摄氏度)。水解是一级反应,与pH无关,观察到的平均(+/- SD)速率常数(kobs)为2.38 +/- 0.6 X 10(-3)h-1。没有观察到明显的缓冲液催化作用。根据TLC,HPLC和质谱研究,1最初降解为氨基磺酸1,7-庚烷单基酯,随后降解为1,7-庚二醇。通过富集18 O的水反应混合物的质谱法评估键裂解的位点。观察到独家的C-O键裂变。可以假定几种降解1的机理。