Labeled oxazaphosphorines for applications in mass spectrometry studies. 2. Synthesis of deuterium-labeled 2-dechloroethylcyclophosphamides and 2- and 3-dechloroethylifosfamides
作者:James B. Springer、O. Michael Colvin、Susan M. Ludeman
DOI:10.1002/jlcr.3142
日期:2014.2
The prodrugs cyclophosphamide (CP) and ifosfamide (IF) each metabolize to an active alkylating agent through a cytochrome P450-mediated oxidation at the C-4 position. Competing with this activation pathway are enzymatic oxidations at the exocyclic α and α′ carbons, which result in dechloroethylation of CP and IF. The incidence of oxidation at one position relative to another is believed to be at least one factor underlying the high degree of interpatient variability in both CP and IF pharmacokinetics. As standards for the mass spectrometry quantification of dechloroethylation, the following were synthesized: (1) [4,4,5,5-2H4]-2-dechloroethylcyclophosphamide (equivalent to [4,4,5,5-2H4]-3-dechloroethylifosfamide); (2) [α,α,4,4,5,5-2H6]-2-dechloroethylcyclophosphamide (equivalent to [α,α,4,4,5,5-2H6]-3-dechloroethylifosfamide); and (3) [α,α,4,4,5,5-2H6]-2-dechloroethylifosfamide. The common precursor to all of the target compounds was [2,2,3,3-2H4]-3-aminopropanol. A one-pot reaction of this compound with POCl3 and unlabeled or labeled 2-chloroethylamine hydrochloride gave the d4 and d6 labeled 2-dechloroethylcyclophosphamides. The construction of the 2-dechloroethylifosfamide from the aminopropanol required five discreet steps. Optimization of the synthetic pathways and stability studies are discussed.
环磷酰胺原药(CP)和伊福酰胺原药(IF)都会通过细胞色素 P450 介导的 C-4 位氧化作用代谢为活性烷化剂。与这一活化途径竞争的是外环 α 和 α′ 碳的酶促氧化,从而导致 CP 和 IF 的脱氯乙基化。一个位置的氧化发生率相对于另一个位置的氧化发生率被认为是 CP 和 IF 药代动力学中患者间差异较大的至少一个因素。作为脱氯乙基化的质谱定量标准,合成了以下物质:(1) [4,4,5,5-2H4]-2-脱氯乙基环磷酰胺(相当于 [4,4,5,5-2H4]-3-脱氯乙基伊福酰胺);(2) [α,α,4,4,5,5-2H6]-2-脱氯乙基环磷酰胺(相当于 [α,α,4,4,5,5-2H6]-3-脱氯乙基异磷酰胺);以及 (3) [α,α,4,4,5,5-2H6]-2-脱氯乙基异磷酰胺。所有目标化合物的共同前体都是[2,2,3,3-2H4]-3-氨基丙醇。将这种化合物与 POCl3 和未标记或标记的 2-氯乙胺盐酸盐进行一锅反应,可得到 d4 和 d6 标记的 2-脱氯乙基环磷酰胺。从氨基丙醇制备 2-脱氯乙基环磷酰胺需要五个不同的步骤。本文讨论了合成途径的优化和稳定性研究。