Relationships between structure and kinetics of cyclization of 2-aminoaryl amides: potential prodrugs of cyclization-activated aromatic mustards
作者:Graham J. Atwell、Bridget M. Sykes、Charmian J. O'Connor、William A. Denny
DOI:10.1021/jm00029a009
日期:1994.2
rate-determining step being formation of the tetrahedral intermediate. These model studies suggest that the phenyldimethylacetamide system could be developed as a prodrug system for the bioreductively-triggered release of amines. Further substantial rate enhancements appear possible by alterations in the geometry of the system, whereas substitution of electron-withdrawing groups (required to raise the
提出具有通用结构I的2-硝基芳基酰胺作为生物可还原的前药,其能够通过四面体中间体III通过自发环化所得的2-氨基芳基酰胺II而在生物活化时释放细胞毒性的氨基苯胺芥子Ⅴ。该概念允许单独优化影响硝基还原和芥菜反应性的取代基效果。合成了一系列的模型2-氨基芳基酰胺,并研究了它们的环化率。在pH 2.4下,它们的变化范围是50,000倍以上(从0.00040到21 min-1的穗粒)。对于详细研究的三种化合物,速率与pH呈线性关系,表明在所研究的pH范围内,速率决定步骤的机理没有变化。氨基的亲核性对环化动力学影响不大,而吸电子基团会减慢速率。化合物的几何形状也很重要,其结构活性关系表明该分子的预组织可大大提高环化速率。相反,各种基团对离去的苯胺的4-取代对环化反应的影响很小。这些结果与确定四面体中间体的速率决定步骤是一致的。这些模型研究表明,可以将苯基二甲基乙酰胺系统开发为生物还原触发释放胺的前药