CAS No 141505-33-1 , 2-[[4-[(4R)-4-methyl-6-oxo-4,
5-dihydro-1H-pyridazin-3-yl]phenyl]hydrazinylidene]propanedinitrile

Title: Levosimendan
CAS Registry Number: 141505-33-1
CAS Name: [[4-[(4R)-1,4,5,6-Tetrahydro-4-methyl-6-oxo-3-pyridazinyl]phenyl]hydrazono]propanedinitrile
Synonyms: (-)-[p[(R)-1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl]phenyl]hydrazone mesoxalonitrile; (R)-simendan
Manufacturers' Codes: OR-1259
Trademarks: Simdax (Orion)
Molecular Formula: C14H12N6O
Molecular Weight: 280.28
Percent Composition: C 59.99%, H 4.32%, N 29.98%, O 5.71%
Literature References: Bioactive enantiomer of racemate, simendan. Positive inotropic agent with vasodilating activity. Binds to and sensitizes the myocardial contractile protein, troponin C, to calcium, thereby stabilizing the troponin conformation needed to trigger muscle contraction. Prepn: R. J. Backstrom et al., GB 2251615; P. Nore et al., US 5569657 (1992, 1996 both to Orion). Pharmacology: A. F. E. Rump et al., Pharmacol. Toxicol. 74, 244 (1994). Binding studies: P. Pollesello et al., J. Biol. Chem. 269, 28584 (1994). HPLC determn in plasma: M. Karlsson et al., Biomed. Chromatogr. 11, 54 (1997). Clinical pharmacokinetics: E.-P. Sandell et al., J. Cardiovasc. Pharmacol. 26, Suppl. 1, S57 (1995). Review of mechanism of action: H. Haikala, I.-B. Lindén, ibid., S10-S19 (1995); of pharmacology, toxicology and clinical evaluation: P. S. Pagel et al., Cardiovasc. Drug Rev. 14, 286-316 (1996). Comparison with dobutamine, q.v., in heart failure: F. Follath et al., Lancet 360, 196 (2002).
Properties: Yellow crystalline powder, mp 210-214°. [a]D25 -566° (tetrahydrofurane/methanol). Soluble in water. pKa 6.3. LD50 in male, female mice, male rats (mg/kg): 156, 152, 103 orally; 32, 50, 57 i.v. (Pagel).
Melting point: mp 210-214°
pKa: pKa 6.3
Optical Rotation: [a]D25 -566° (tetrahydrofurane/methanol)
Toxicity data: LD50 in male, female mice, male rats (mg/kg): 156, 152, 103 orally; 32, 50, 57 i.v. (Pagel)
Therap-Cat: Cardiotonic.
Keywords: Cardiotonic.