7H-Pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-ethoxy-5-(1-piperazinylsulfonyl)phenyl]-1,6-dihydro-3-propyl-

2-[5-(4-Ethyl-piperazine-1-sulfonyl)-2-methoxy-phenyl]-5-methyl-7-propyl-3,7-dihydro-pyrrolo[2,3-d]pyrimidin-4-one Sildenafil Impurity 18 Benzamide, 3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-N-[2-(dimethylamino)ethyl]-4-propoxy- Imidazo[5,1-f][1,2,4]triazin-4(1H)-one, 2-[5-[(4-ethyl-1-piperazinyl)sulfonyl]-2-propoxyphenyl]-5-methyl-7-propyl- Sildenafil Impurity 78

Nitroso-prodenafil Des-N-Ethyl 3,5-DiMethylacetildenafil 7H-Pyrazolo[4,3-d]pyrimidin-7-one, 1,6-dihydro-1-methyl-5-[5-[2-(4-methyl-1-piperazinyl)acetyl]-2-propoxyphenyl]-3-propyl- Sildenafil Impurity 3 1-Decarboxyl-1-(broMoacetyl) Norneovardenafil

1-[(4-Ethoxy-3-formylphenyl)sulfonyl]-4-methylpiperazine 7H-Pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-ethoxy-5-[(4-methyl-1-piperazinyl)sulfonyl]phenyl]-6-ethyl-1,6-dihydro-1-methyl-3-propyl- 7H-Pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-ethoxy-5-[2-(4-ethyl-3-oxo-1-piperazinyl)-2-hydroxyethyl]phenyl]-1,6-dihydro-1-methyl-3-propyl- 5,6-diethyl-2-(5-((4-methylpiperazin-1-yl)sulfonyl)-2-propoxyphenyl)pyrimidin-4(3H)-one Piperazonifil

Sildenafil Impurity 5-[5-[(3S,5R)-3,5-dimethylpiperazin-1-yl]sulfonyl-2-propoxyphenyl]-1-methyl-3-(2-methylpropyl)-4H-pyrazolo[4,3-d]pyrimidin-7-one 7H-Pyrazolo[4,3-d]pyrimidin-7-one, 5-[2-ethoxy-5-[[4-(1-methylethyl)-1-piperazinyl]sulfonyl]phenyl]-1,6-dihydro-1-methyl-3-propyl-