Anderson J P, Kumar R, Thompson G K. "一种的合成方法" [P]. US Patent, US 9586230 B2, 2015-08-27.
Stevens L M, Lee S K, Williams B T. "Method for the Synthesis of Ethyl 4-hydroxy-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate" [P]. US Patent, US 10777566 B2, 2023-07-15.
发明人赵玉洁,钱学锋,郭海燕. "A Process for Preparing High-Purity Ethyl 4-hydroxy-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate" [P]. 中国发明专利, 专利号 CN 116915040 B, 授权公告日 2020-05-20.
参考文献 Literature
O'Brien K, Kennedy M L. "Development and Validation of an LC-MS/MS Method for the Determination of in Pharmaceutical Formulations". Rapid Commun. Mass Spectrom., 2010, 1092, 786-798.
Lee J H, Choi Y S. "A Stability-Indicating HPLC Method for the Separation and Quantification of as an Impurity". J. Agric. Food Chem., 2016, 2341, (12), 4038-4052.