5-[2-ethoxy-5-[2-(4-methylpiperazin-1-yl)acetyl]phenyl]-1-methyl-3-propyl-4H-pyrazolo[4,3-d]pyrimidin-7-one; 5-[2-ETHOXY-5-[2-(4-METHYL-(PIPERAZIN-1-YL))ACETYL]PHENYL]-1,6-DIHYDRO-1-METHYL-3-PROPYL-7H-PYRAZOLO[4,3-D]PYRIMIDIN-7-ONE; Nor Acetildenafil; 5-[2-Ethoxy-5-[2-(4-methyl-1-piperazinyl)acetyl]phenyl]-1,6-dihydro-1-methyl-3-propyl-7H-pyrazolo[4,3-d]pyrimidin-7-one