During the oxidative (10% H2O2) degradation of suvorexant drug substance, around 1.0% of one impurity and less than 1.0% four impurities were found by a new high-performance liquid chromatography (HPLC) assay and related substance method. The mass numbers of 1.0% impurity was 469 [M + H]+, remaining four impurities were 172 [M + H]+, 467 [M + H]+, 483 [M + H]+ and 485 [M + H]+. The 469 [M + H]+, 485[M + H] and 172 [M + H]+ impurities were characterized by using the LC-MS/MS, HR-MS and 1D, 2D NMR spectroscopic data. The 172 [M + H]+ impurity was prepared synthetically and co-injected in HPLC. The retention time of synthesized 172 [M + H]+ impurity was matching with the unknown degradation impurity in HPLC. The developed mass compatible HPLC and ultra performance liquid chromatography methods were validated for drug substance and process impurities by following ICH Q2 (R1) guidelines.

中文翻译：

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LC-MS / MS，HR-MS和1D，2D NMR表征5种氧化降解杂质和1种工艺杂质的含量：通过HPLC和UPLC验证了5种氧化降解杂质和1种工艺杂质的含量。

通过新型高效液相色谱（HPLC）分析和相关物质方法，在suvorexant原料药的氧化（10％H2O2）降解过程中，发现约1.0％的一种杂质和少于1.0％的四种杂质。1.0％杂质的质量数为469 [M + H] +，其余四个杂质为172 [M + H] +，467 [M + H] +，483 [M + H] +和485 [M + H] +。使用LC-MS / MS，HR-MS和1D，2D NMR光谱数据对469 [M + H] +，485 [M + H] +和172 [M + H] +杂质进行了表征。合成了172 [M + H] +杂质，并共注入HPLC中。合成的172 [M + H] +杂质的保留时间与HPLC中未知的降解杂质相匹配。