英文别名Sildenafil impurity; 3-(6,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,5-d]pyrimidin-5-yl)-4-ethoxy-ethyl ester Benzenesulfonic acid; Sildenafil Impurity 17; Ethyl 4-Ethoxy-3-(1-methyl-7-oxo-3-propyl-6H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonate; ethyl 4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonate; Ethyl 4-ethoxy-3-(1-methyl-7-oxo-3-propyl-4,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonate; Sildenafil Impurity J; Benzenesulfonic acid, 3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxy-, ethyl ester 
