发明人何建平,黄志刚,张德明. "Method for the Synthesis of Ensifentrine Impurity 4" [P]. 中国发明专利, 专利号 CN 109879199 A, 授权公告日 2025-02-12.
发明人朱建伟,李文辉,韩伟. "A Process for Preparing High-Purity Ensifentrine Impurity 4" [P]. 中国发明专利, 专利号 CN 117493659 B, 授权公告日 2021-10-26.
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