英文名称
3-(6,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxy-ethyl ester Benzenesulfonic acid
Standards; Pharmaceutical/API Drug Impurities/Metabolites;
3-(6,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxy-ethyl ester Benzenesulfonic acid is used in the preparation of sildenafil impurity for pharmaceutical quality control by esterification.