英文别名5-(5-Carboxy-2-ethoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one; 4-ethoxy-3-(1-methyl-7-oxo-3-propyl-4H-pyrazolo[4,3-d]pyrimidin-5-yl)benzoic acid; Acetil acid; 3-(6,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxybenzoic acid; Benzoic acid, 3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxy-; Sildenafil Impurity 4; Sildenafil Carboxylic Acid Impurity; Sildenafil Impurity IV-4; Sildenafil Carboxylic Acid Derivative 
