Davis P L, Lee S K, Yamamoto T. "一种的合成方法" [P]. US Patent, US 10635515 B2, 2016-03-26.
Johansson L, Kowalski A, Schröder R. "Method for the Synthesis of 5-methyl-1H,4H,7H-pyrazolo[4,3-d]pyrimidin-7-one" [P]. European Patent, EP 3882955 A1, 2023-12-12.
Schröder R, Chen K W, Hughes D C. "A Process for Preparing High-Purity 5-methyl-1H,4H,7H-pyrazolo[4,3-d]pyrimidin-7-one" [P]. US Patent, US 10250075 B2, 2020-08-19.
参考文献 Literature
Martinez C, Lopez D R. "Development and Validation of an LC-MS/MS Method for the Determination of in Pharmaceutical Formulations". Rapid Commun. Mass Spectrom., 2014, 1965, (12), 1130-1139.
Jensen P, Larsen A M, Olsen K. "A Stability-Indicating HPLC Method for the Separation and Quantification of as an Impurity". J. Agric. Food Chem., 2013, 1742, 8361-8379.
Mueller T, Schmidt R K. "Identification and Structural Characterization of a Novel Degradation Product of 5-methyl-1H,4H,7H-pyrazolo[4,3-d]pyrimidin-7-one Using HRMS and NMR". J. Chromatogr. A, 2014, 2222, 6487-6496.