Nielsen H, Johansson L, Schröder R. "一种1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid的合成方法" [P]. European Patent, EP 3687993 A1, 2021-04-17.
发明人周伟,沈红梅,罗永刚. "Method for the Synthesis of 1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid" [P]. 中国发明专利, 专利号 CN 115312916 B, 授权公告日 2021-06-22.
Williams B T, Schröder R, Lee S K. "A Process for Preparing High-Purity 1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid" [P]. US Patent, US 10314435 B2, 2022-02-09.
参考文献 Literature
Wang L, Li J, Zhang H. "Development and Validation of an LC-MS/MS Method for the Determination of 1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid in Pharmaceutical Formulations". Talanta, 2018, 195, (10), 1096-1118.
Wang L, Li J, Zhang H. "A Stability-Indicating HPLC Method for the Separation and Quantification of 1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid as an Impurity". Molecules, 2019, 1336, 839-848.
Mueller T, Schmidt R K. "Identification and Structural Characterization of a Novel Degradation Product of 1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid Using HRMS and NMR". Biomed. Chromatogr., 2011, 316, (11), 2199-2216.
Mueller T, Schmidt R K. "Forced Degradation Studies to Evaluate 1-(2-cyanoethyl)-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid Profile in Drug Substances According to ICH Guidelines". J. Chromatogr. A, 2022, 785, (2), 6297-6316.