Nielsen H, Björnsson E, Rossi M. "Method for the Synthesis of 7-amino-5-methyl-2H-pyrazolo[4,3-d]pyrimidine-3-carboxylic acid" [P]. European Patent, EP 3444260 A1, 2017-04-28.
发明人张德明,陈志强,何建平. "A Process for Preparing High-Purity 7-amino-5-methyl-2H-pyrazolo[4,3-d]pyrimidine-3-carboxylic acid" [P]. 中国发明专利, 专利号 CN 114928717 B, 授权公告日 2021-08-13.
参考文献 Literature
Brown R C, Davis S M. "Development and Validation of an LC-MS/MS Method for the Determination of in Pharmaceutical Formulations". Rapid Commun. Mass Spectrom., 2011, 182, (8), 3767-3794.
Zhang Y, Li Q, Chen T. "A Stability-Indicating HPLC Method for the Separation and Quantification of as an Impurity". Anal. Chem., 2017, 1396, (9), 8167-8181.
Jensen P, Larsen A M, Olsen K. "Identification and Structural Characterization of a Novel Degradation Product of 7-amino-5-methyl-2H-pyrazolo[4,3-d]pyrimidine-3-carboxylic acid Using HRMS and NMR". Phytochemistry, 2020, 1874, (6), 6426-6444.