Brown S R, Klinger H, Roberts E F. "一种的合成方法" [P]. US Patent, US 9132829 B2, 2017-08-26.
Björnsson E, Kowalski A, Mueller T C. "Method for the Synthesis of 6-Hydroxy-1-(4-methoxyphenyl)-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid" [P]. European Patent, EP 3614832 A1, 2022-05-12.
Thompson G K, Patel M V, O'Brien P Q. "A Process for Preparing High-Purity 6-Hydroxy-1-(4-methoxyphenyl)-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid" [P]. US Patent, US 10652862 B2, 2024-10-06.
参考文献 Literature
Chen X Y, Liu M, Zhao W Q. "Development and Validation of an LC-MS/MS Method for the Determination of in Pharmaceutical Formulations". Rapid Commun. Mass Spectrom., 2024, 1211, (9), 1841-1852.
Martinez C, Lopez D R. "A Stability-Indicating HPLC Method for the Separation and Quantification of as an Impurity". J. Agric. Food Chem., 2017, 1247, (6), 9151-9176.
Kim S H, Park J Y. "Identification and Structural Characterization of a Novel Degradation Product of 6-Hydroxy-1-(4-methoxyphenyl)-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid Using HRMS and NMR". Chromatographia, 2023, 184, 8474-8481.