3-[2-(4-methoxyphenyl)-3H-benzimidazol-5-yl]-4-methyl-4,5-dihydro-1H-pyridazin-6-one; (5RS)-6-[2-(4-Methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-4,5-dihydropyridazin-3(2H)-one; 4,5-Dihydro-6-[2-(4-methoxyphenyl)-1H-benzimidazol-6-yl]-5-methyl- 3(2H)-pyridazinone; 4,5Dihydro-6-[2-(4-methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-3(2H)-pyridazinone; (RS)-6-[2-(4-Methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-4,5-dihydropyridazin-3(2H)-one; 6-(2-(4-Methoxyphenyl)-1H-benzo[d]imidazol-6-yl)-5-methyl-4,5-dihydropyridazin-3(2H)-one; rac Pimobendan; Acardi; 3(2H )-Pyridazinone, 4,5-dihydro-6-[2-(4-methoxyphenyl)-1H -benzimidazol-5-yl]-5-methyl-, (±)-; (±)-4,5-Dihydro-6-[2-(p-methoxyphenyl)-5-benzimidazolyl]-5-methyl-3(2H )-pyridazinone; 6-[2-(4-Methoxyphenyl)-1H -benzimidazol-5-yl]-5-methyl-4,5-dihydropyridazin-3(2H )-one (USP)