36725-28-7

Basic information

• Product Name: 6-(4-Aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone
• Synonyms: LEVOSIMENDAN DAZINONES INTERMEDIATES;6-(4-AMINOPHENYL)-4,5-DIHYDRO-5-METHYL-3(2H)PYRIDAZINONE;6-(4-AMINO-PHENYL)-5-METHYL-4,5-DIHYDRO-2H-PYRIDAZIN-3-ONE;(R)-6-(4-AMINOPHENYL)-4,5-DIHYDRO-5-METHYLPYRIDAZIN-3(2H)ONE;6-(4-Aminophenyl)-5-methylpyridazin-3(2H)one;6-(4''-AMINOPHENYL)-4,5-DIHYDRO-5-METHYLPYRIDAZIN-3-ONE;ICI 109,081;6-(p-Aminophenyl)-5-methyl-4,5-dihydro-3(2H)-pyridazinone
• CAS NO: 36725-28-7
• Molecular Formula: C₁₁H₁₃N₃O
• Molecular Weight: 203.24
• Product Categories: (intermediate of levosimendan)
• Mol File: 36725-28-7.mol
• Article Data: 11

Chemical Properties

• Melting Point: 194.0 to 198.0 °C
• Appearance: /
• Density: 1.3 g/cm³
• Refractive Index: 1.652
• Storage Temp.: Keep in dark place,Sealed in dry,Room Temperature
• Solubility: DMSO (Slightly), Methanol (Slightly, Sonicated)
• PKA: 13.90±0.60(Predicted)
• CAS DataBase Reference: 6-(4-Aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone(CAS DataBase Reference)
• NIST Chemistry Reference: 6-(4-Aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone(36725-28-7)
• EPA Substance Registry System: 6-(4-Aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone(36725-28-7)

Safety Data

• Hazardous Substances Data: 36725-28-7(Hazardous Substances Data)

Usage

Uses

AMDP3 (4-Aminophenyl)-4-methyl-4,5-dihydro-1H-pyridazin-6-one) acts as a cardiac troponin effecter, resulting in activation of cardiac muscle contractions. It’s an analogue to Levosimendan (L378000), positive inotropic agent with vasodilating activity.

InChI:InChI=1/C11H13N3O/c1-7-6-10(15)13-14-11(7)8-2-4-9(12)5-3-8/h2-5,7H,6,12H2,1H3,(H,13,15)

Synthetic route

4-(4-aminophenyl)-3-methyl-4-oxobutanoic acid hydrochloride (120757-13-3) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
With hydrazine hydrate In ethanol for 3h; Heating;	98.4%
With hydrazine hydrate In water for 1.5h; Heating;	87%
With hydrazine hydrate at 80℃; for 18h;	65%

SKF 93741 (36725-27-6) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
With hydrogenchloride for 1.25h; Heating;	76%

(3S)-4-(4-aminophenyl)-3-methyl-4-oxobutanoic acid → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
With hydrazine hydrate In propan-1-ol at 20 - 100℃; for 4h;	49%

4-(4-acetamidophenyl)-4-oxobutanoic acid (5473-15-4) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 6 steps 1: 62 percent / H2O / 1) room temperature, overnight, 2) steam bath, 2 h 2: conc. H2SO4 / 1 h / Heating 3: pyridine 4: H2 / Raney Nickel / methanol / 0.33 h / 1034.3 Torr 5: 90 percent / hydrazine hydrate / ethanol; H2O / 2 h / Heating 6: 76 percent / 1 M aq. HCl / 1.25 h / Heating View Scheme

N-[4-(2-chloro-1-oxopropyl)phenyl]acetamide (81112-08-5) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: 1) NaH / 1) DMF, room temperature, overnight, 2) DMF, 110 deg C, 3 h 2: 1.) HCl/EtOH, 2.) 6N aq. HCl / 2 h / Heating; 1.) reflux, 2 h, 2.) reflux, 2 h 3: 87 percent / hydrazine hydrate / H2O / 1.5 h / Heating View Scheme

3-(4-Acetylamino-benzoyl)-but-3-enoic acid methyl ester (120757-16-6) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: H2 / Raney Nickel / methanol / 0.33 h / 1034.3 Torr 2: 90 percent / hydrazine hydrate / ethanol; H2O / 2 h / Heating 3: 76 percent / 1 M aq. HCl / 1.25 h / Heating View Scheme

methyl 3-(4-acetaminobenzoyl)butyrate (120757-17-7) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: 90 percent / hydrazine hydrate / ethanol; H2O / 2 h / Heating 2: 76 percent / 1 M aq. HCl / 1.25 h / Heating View Scheme

4-(4-Amino-phenyl)-4-oxo-3-piperidin-1-ylmethyl-butyric acid methyl ester (120757-15-5) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 4 steps 1: pyridine 2: H2 / Raney Nickel / methanol / 0.33 h / 1034.3 Torr 3: 90 percent / hydrazine hydrate / ethanol; H2O / 2 h / Heating 4: 76 percent / 1 M aq. HCl / 1.25 h / Heating View Scheme

2-ethoxycarbonyl-3-(4-acetamidobenzoyl)butyric acid ethyl ester (81937-39-5) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: 1.) HCl/EtOH, 2.) 6N aq. HCl / 2 h / Heating; 1.) reflux, 2 h, 2.) reflux, 2 h 2: 87 percent / hydrazine hydrate / H2O / 1.5 h / Heating View Scheme
Stage #1: 2-ethoxycarbonyl-3-(4-acetamidobenzoyl)butyric acid ethyl ester With sodium hydroxide In water for 4h; Stage #2: With hydrogenchloride In water at 100℃; for 3h; pH=1; Further stages;	1.8 g

3-(4-acetamidobenzoyl)-4-(N-piperidinyl)butanoic acid (120757-14-4) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 5 steps 1: conc. H2SO4 / 1 h / Heating 2: pyridine 3: H2 / Raney Nickel / methanol / 0.33 h / 1034.3 Torr 4: 90 percent / hydrazine hydrate / ethanol; H2O / 2 h / Heating 5: 76 percent / 1 M aq. HCl / 1.25 h / Heating View Scheme

Acetanilid (103-84-4) + dichloroiodo-benzene → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 4 steps 1: 61 percent / AlCl3 / CH2Cl2 / Ambient temperature; overnight 2: 1) NaH / 1) DMF, room temperature, overnight, 2) DMF, 110 deg C, 3 h 3: 1.) HCl/EtOH, 2.) 6N aq. HCl / 2 h / Heating; 1.) reflux, 2 h, 2.) reflux, 2 h 4: 87 percent / hydrazine hydrate / H2O / 1.5 h / Heating View Scheme

(5S)-6-(4-aminophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one (101328-84-1) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
With sodium hydroxide at 90℃;

N-(4-propionylphenyl)acetamide (16960-49-9) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: bromine / chloroform 1.2: 24 h / 20 °C / pH 8 2.1: sodium ethanolate / ethanol / Cooling with ice 2.2: 8.17 h / 35 - 75 °C 3.1: sodium hydroxide / water / 4 h 3.2: 3 h / 100 °C / pH 1 View Scheme

N-(4-(2-bromopropionyl)phenyl)acetamide (63514-63-6) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: sodium ethanolate / ethanol / Cooling with ice 1.2: 8.17 h / 35 - 75 °C 2.1: sodium hydroxide / water / 4 h 2.2: 3 h / 100 °C / pH 1 View Scheme

Acetanilid (103-84-4) → 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: carbon disulfide; aluminum (III) chloride / 50 °C 2.1: bromine / chloroform 2.2: 24 h / 20 °C / pH 8 3.1: sodium ethanolate / ethanol / Cooling with ice 3.2: 8.17 h / 35 - 75 °C 4.1: sodium hydroxide / water / 4 h 4.2: 3 h / 100 °C / pH 1 View Scheme

3-bromopropylamine tert-butylcarbamate (83948-53-2) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → tert-butyl {3-[3-(4-aminophenyl)-4-methyl-6-oxo-5,6-dihydropyridazin-1(4H)-yl]propyl}carbamate

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With sodium hydride In N,N-dimethyl-formamide Stage #2: 3-bromopropylamine tert-butylcarbamate With tetra-(n-butyl)ammonium iodide In N,N-dimethyl-formamide at 20℃; Cooling with ice;	100%

3-Bromopropionyl chloride (15486-96-1) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-<4-(3-bromopropionamido)phenyl>-5-methyl-4,5-dihydro-3(2H)-pyridazinone (111794-34-4)

Conditions	Yield
In acetonitrile for 3h; Heating;	99%
With sodium hydrogencarbonate In dichloromethane

C9H6ClNO4 + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)-6-nitrobenzo[d][1,3]dioxole-5-carboxamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 0 - 20℃;	88.7%

6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → C22H23N7O2

Conditions	Yield
With hydrogenchloride; sodium nitrite In water at 0℃; for 1h;	86%

3-bromopropanol methyl ether (36865-41-5) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-(4-aminophenyl)-2-(3-methoxypropyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With sodium hydride In N,N-dimethyl-formamide; mineral oil at 0 - 20℃; for 0.5h; Stage #2: 3-bromopropanol methyl ether In N,N-dimethyl-formamide; mineral oil at 0 - 20℃;	85%

2,4,5-trifluoro-3-methylbenzamide (112822-86-3) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 2,4,5-trifluoro-3-methyl-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 20℃;	84.2%

3-methyl-4-nitro-benzoyl chloride (35675-46-8) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 3-methyl-4-nitro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 0 - 20℃;	83.2%

6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-(4-hydrazinophenyl)-5-methyl-4,5-dihydro-2H-pyridazin-3-one hydrochloride

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With hydrogenchloride; sodium nitrite at 0℃; for 0.5h; Stage #2: With hydrogenchloride; tin(ll) chloride at 0℃; for 1h;	83%

4-chloro-6-methoxy-2-methylquinoline (50593-73-2) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → C22H22N4O2

Conditions	Yield
In butan-1-ol for 4h; Heating;	83%

5-chloro-2-nitrobenzoyl chloride (41994-44-9) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 5-chloro-2-nitro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 20℃;	76.3%

ethyl iodide (75-03-6) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-(4-aminophenyl)-2-ethyl-5-methyl-4,5-dihydropyridazin-3(2H)-one

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With tetra-(n-butyl)ammonium iodide; sodium hydride In N,N-dimethyl-formamide; mineral oil at 0℃; for 0.5h; Stage #2: ethyl iodide In N,N-dimethyl-formamide; mineral oil at 20℃; Reagent/catalyst;	76%

N-carbobenzoxy-β-alanine-p-nitrophenyl ester (3642-91-9) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-<4-<3-<(benzyloxycarbonyl)amino>propionamido>phenyl>-5-methyl-4,5-dihydro-3(2H)-pyridazinone (111794-60-6)

Conditions	Yield
In N,N-dimethyl-formamide	73%

Cyclopentyl bromide (137-43-9) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-(4-aminophenyl)-2-cyclopentyl-5-methyl-4,5-dihydropyridazin-3(2H)-one

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With sodium hydride In N,N-dimethyl-formamide; mineral oil at 0℃; for 1h; Stage #2: Cyclopentyl bromide In N,N-dimethyl-formamide; mineral oil at 20℃; for 2h;	71%

4-chloro-2-nitro-benzoyl chloride (41995-04-4) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 4-chloro-2-nitro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 0 - 20℃;	65.7%

2,4-dichloro-5-fluorobenzoyl chloride (86393-34-2) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 2,4-dichloro-5-fluoro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 20℃;	65.4%

dimethyl N-cyanodithioiminocarbonate (10191-60-3) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-<4-(N'-cyano-S-methylisothioureido)phenyl>-5-methyl-4,5-dihydropyridazin-3(2H)-one (99591-85-2, 123466-25-1)

Conditions	Yield
With pyridine for 3.5h; Heating;	65%

3-Chloro-2,4,5-trifluorobenzoyl chloride (101513-78-4) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 3-chloro-2,4,5-trifluoro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 20℃;	63.8%

di(succinimido) carbonate (74124-79-1) + 2,3-dihydro-1H-pyrrolo[3,4-c]pyridine dihydrogen chloride (6000-50-6) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → N-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl]-1,3-dihydro-2H-pyrrolo[3,4-c]pyridine-2-carboxamide

Conditions	Yield
Stage #1: di(succinimido) carbonate; 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With dmap In tetrahydrofuran at 20℃; for 72h; Stage #2: 2,3-dihydro-1H-pyrrolo[3,4-c]pyridine dihydrogen chloride With triethylamine In tetrahydrofuran; N,N-dimethyl-formamide	63%

1,3-Dihydro-isobenzofuran-5-carbonyl chloride (153967-93-2) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzo[d][1,3]dioxole-5-carboxamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 0 - 20℃;	60.5%

4-chloro-2,6-dimethylquinoline (6270-08-2) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → C22H22N4O

Conditions	Yield
In butan-1-ol for 4h; Heating;	60%

pyruvic acid methyl ester (600-22-6) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → methyl 2-(2-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)hydrazono)propanoate

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With hydrogenchloride; sodium nitrite In water at 0℃; for 0.166667h; Stage #2: With hydrogenchloride; tin(II) chloride dihdyrate In water at 0℃; for 0.166667h; Stage #3: pyruvic acid methyl ester In water at 20℃; for 0.5h;	60%

2,3-dichlorobenzoyl chloride (2905-60-4) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 2,3-dichloro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 0 - 20℃;	59.5%

1-trimethylsiloxy-3-bromo-propane (34714-04-0) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-(4-aminophenyl)-5-methyl-2-{3-[(trimethylsilyl)oxy]propyl}-4,5-dihydropyridazin-3(2H)-one

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With tetra-(n-butyl)ammonium iodide; sodium hydride In N,N-dimethyl-formamide; mineral oil at 0℃; for 0.5h; Stage #2: 1-trimethylsiloxy-3-bromo-propane In N,N-dimethyl-formamide; mineral oil at 20℃;	58%

6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 5-methyl-6-phenyl-4,5-dihydro-2H-pyridazin-3-one (110766-33-1)

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With hydrogenchloride; sodium nitrite In water at 0℃; for 0.333333h; Stage #2: With hypophosphorous acid In water	55%

2-chloropropionyl chloride (7623-09-8) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → amipizone (69635-63-8)

Conditions	Yield
In tetrahydrofuran for 6h; Heating;	54%

2-(tert-butyldimethylsilyloxy)ethyl bromide (86864-60-0) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 6-(4-aminophenyl)-2-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one

Conditions	Yield
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With sodium hydride In N,N-dimethyl-formamide; mineral oil at 20℃; for 0.333333h; Stage #2: With tetra-(n-butyl)ammonium iodide In N,N-dimethyl-formamide; mineral oil for 0.25h; Stage #3: 2-(tert-butyldimethylsilyloxy)ethyl bromide In N,N-dimethyl-formamide; mineral oil at 0 - 20℃; for 14h;	53%
Stage #1: 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone With sodium hydride In N,N-dimethyl-formamide; mineral oil at 20℃; for 0.333333h; Stage #2: 2-(tert-butyldimethylsilyloxy)ethyl bromide With tetra-(n-butyl)ammonium iodide In N,N-dimethyl-formamide; mineral oil at 0 - 20℃; for 14h;

3-chlorobutanoyl chloride (1951-11-7) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 3-Chloro-N-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydro-pyridazin-3-yl)-phenyl]-butyramide (85221-85-8)

Conditions	Yield
In tetrahydrofuran for 6h; Heating;	52%

2,3,4,5-tetrafluorobenzoyl chloride (94695-48-4) + 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone (36725-28-7) → 2,4,3,5-tetrafluoro-N-(4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)phenyl)benzamide

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 20℃;	51.2%

Upstream product

• 36725-27-6 SKF 93741 
• 16960-49-9 N-(4-propionylphenyl)acetamide 
• 63514-63-6 N-(4-(2-bromopropionyl)phenyl)acetamide 
• 103-84-4 Acetanilid 
• 81937-39-5 2-ethoxycarbonyl-3-(4-acetamidobenzoyl)butyric acid ethyl ester 
• 1260774-44-4 (-)-6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone di-p-anisoyl-D-tartrate 
• 50583-51-2 O,O′-di-p-anisoyl-D-tartaric acid 
• 50583-51-2 (2R,3R)-2,3-bis[(4-methoxyphenyl)carbonyloxy]butanedioic acid 
• 101328-84-1 (5S)-6-(4-aminophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one 
• 132298-10-3 N-[4-((R)-2-Chloro-propionyl)-phenyl]-acetamide 
• 132298-12-5 2-[(R)-2-(4-Amino-phenyl)-1-methyl-2-oxo-ethyl]-malonic acid benzyl ester methyl ester 
• 132298-13-6 2-[(R)-2-(4-Amino-phenyl)-1-methyl-2-oxo-ethyl]-malonic acid monomethyl ester 
• 132298-11-4 (R)-1-(4-Amino-phenyl)-2-chloro-propan-1-one 
• 139052-00-9 (R)-4-(4-Acetylamino-phenyl)-3-methyl-4-oxo-butyric acid 

Downstream Products

• 112127-66-9 5-methyl-6-[4-(4-oxo-1,4-dihydropyridin-1-yl)phenyl]-4,5-dihydro-3(2H)-pyridazinone 
• 113118-40-4 (R)-5-methyl-6-[4-(4-oxo-1,4-dihydropyridin-1-yl)phenyl]-4,5-dihydro-3(2H)-pyridazinone 
• 69635-65-0 6-[4-(3-chloro-propionylamino)-phenyl]-5-methyl-4,5-dihydro-2H-pyridazin-3-one 
• 85221-84-7 2-Chloro-N-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydro-pyridazin-3-yl)-phenyl]-butyramide 
• 69635-73-0 6-[4-(2-bromo-propionylamino)-phenyl]-5-methyl-4,5-dihydro-2H-pyridazin-3-one 
• 69635-66-1 6-[4-(4-chloro-butyrylamino)-phenyl]-5-methyl-4,5-dihydro-2H-pyridazin-3-one 
• 134052-12-3 2-{1,1-Dimethyl-2-[4-((R)-4-methyl-6-oxo-1,4,5,6-tetrahydro-pyridazin-3-yl)-phenylamino]-ethyl}-isoindole-1,3-dione 
• 139052-02-1 OR-1896 
• 360794-84-9 (R)-6-(4-hydrazino-phenyl)-5-methyl-4,5-dihydro-2H-pyridazin-3-one 
• 131741-22-5 6-[4-(1,1-diacetylmethylidenehydrazino)phenyl]-4,5-dihydro-5-methylpyridazin-3(2H)one 

Relevant articles and documents

ANTIBODY DRUG CONJUGATES (ADCS) WITH NAMPT INHIBITORS

Conjugate of a binder having formula (AA) wherein AB stands for a binder, Z' stands for a linker, D stands for an active component which is a NAMPT inhibitor and its use as pharmaceuticals.

DIHYDROPYRIDAZINONES SUBSTITUTED WITH PHENYLUREAS

Compounds of formula (I) which are nicotinamide phosphoribosyltransferase (NAMPT) inhibitors and their use for the treatment of hyperproloferative diseases and/or disorders responsive to induction of cell death.

PROCESS FOR PREPARING LEVOSIMENDAN AND INTERMEDIATES FOR USE IN THE PROCESS

In an embodiment, the present invention provides a process for preparing (-)-6-(4- aminophenyl)-5-methylpyridazin-3-(2H)-one, which process comprises: a) reacting racemic 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone of formula (Il) with a chiral tartaric acid derivative to obtain a diastereomeric salt of (-)-6-(4- aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone and the chiral tartaric acid derivative; and b) reacting the diastereomeric salt with a base to obtain (-)-6-(4- aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone. The (-)-6-(4-aminophenyl)-4,5- dihydro-5-methyl-3-(2H)-pyridazinone may be used to prepare levosimendan.