1904-31-0

Basic information

• Product Name: 1-Methyl-1H-pyrazol-3-amine
• Synonyms: 1-METHYL-1H-PYRAZOL-3-AMINE;1-METHYL-1H-PYRAZOL-3-YLAMINE;3-AMINO-1-METHYLPYRAZOLE;AKOS B014443;BUTTPARK 83\09-99;ART-CHEM-BB B014443;1-methyl-3-aminopyrazole;3-Amino-1-methyl-1H-pyrazole
• CAS NO: 1904-31-0
• Molecular Formula: C₄H₇N₃
• Molecular Weight: 97.12
• Product Categories: Imidazoles, Pyrroles, Pyrazoles, Pyrrolidines;Amines;Pyrazoles & Triazoles;Pyrazole;Pyrazoles & Triazoles
• Mol File: 1904-31-0.mol
• Article Data: 4

Chemical Properties

• Boiling Point: 93 °C
• Flash Point: 93.756 °C
• Appearance: Colorless to light yellow liquid
• Density: 1.224 g/cm³
• Refractive Index: 1.5420-1.5460
• Storage Temp.: under inert gas (nitrogen or Argon) at 2–8 °C
• PKA: 4.04±0.10(Predicted)
• Water Solubility: Slightly soluble in water.
• Sensitive: Air Sensitive
• CAS DataBase Reference: 1-Methyl-1H-pyrazol-3-amine(CAS DataBase Reference)
• NIST Chemistry Reference: 1-Methyl-1H-pyrazol-3-amine(1904-31-0)
• EPA Substance Registry System: 1-Methyl-1H-pyrazol-3-amine(1904-31-0)

Safety Data

• Hazard Codes: Xn,Xi
• Statements: 22-36/37/38
• Safety Statements: 26-36/37/39
• RIDADR: UN2735
• HazardClass: IRRITANT
• Hazardous Substances Data: 1904-31-0(Hazardous Substances Data)

Usage

Chemical Properties

Colorless to light yellow liqui

Uses

It is an important raw material and intermediate used in organic synthesis, pharmaceuticals, agrochemicals and dyestuff.

InChI:InChI=1/C4H7N3/c1-7-3-2-4(5)6-7/h2-3H,1H3,(H2,5,6)

Synthetic route

1-methyl-3-nitro-1H-pyrazole (54210-32-1) → 1,1'-dimethyl-3-azoxypyrazole (132038-69-8) + methyl-1 amino-3 pyrazole (1904-31-0)

Conditions	Yield
With hydrazine hydrate; nickel In ethanol Heating;	A 54% B 7.1 g

4-iodo-1-methyl-3-nitro-1H-pyrazole (75092-34-1) → methyl-1 amino-3 pyrazole (1904-31-0)

Conditions	Yield
With hydrogenchloride; tin(ll) chloride In water at 30℃; for 2h; Reduction;	51%

N-(1-methyl-3-pyrazolyl)-acetoacetamide (91027-92-8) → 2,4-dimethyl-2H-pyrazolo<3,4-b>pyridin-6(7H)-one (73810-75-0) + methyl-1 amino-3 pyrazole (1904-31-0)

Conditions	Yield
With hydrogenchloride In ethanol for 3h; Heating;	A 21% B 15%

1-methyl-3-nitro-1H-pyrazole (54210-32-1) → methyl-1 amino-3 pyrazole (1904-31-0)

Conditions	Yield
With hydrogenchloride; tin(ll) chloride Reduction;
With hydrogen In methanol for 3h;

pivaloyl chloride (3282-30-2) + methyl-1 amino-3 pyrazole (1904-31-0) → C9H15N3O (1135343-82-6)

Conditions	Yield
With dmap; triethylamine In dichloromethane at 0 - 20℃;	100%

acetyl chloride (75-36-5) + methyl-1 amino-3 pyrazole (1904-31-0) → N-(1-methyl-1H-pyrazol-3-yl)-acetamide hydrochlorid

Conditions	Yield
In tetrahydrofuran at 20℃; for 2h;	100%
In tetrahydrofuran at 0 - 20℃; for 2h;	100%

3-(chlorosulfonyl)benzenesulfonyl fluoride (2489-52-3) + methyl-1 amino-3 pyrazole (1904-31-0) → 3-(N-(1-methyl-1H-pyrazol-3-yl)sulfamoyl)benzene-1-sulfonyl fluoride

Conditions	Yield
With pyridine In chloroform at 20℃; for 48h; chemoselective reaction;	99%

4-(chlorosulfonyl)benzenesulfonyl fluoride + methyl-1 amino-3 pyrazole (1904-31-0) → C10H10FN3O4S2

Conditions	Yield
With pyridine In chloroform at 20℃; for 48h; chemoselective reaction;	99%

bromochlorobenzene (106-39-8) + methyl-1 amino-3 pyrazole (1904-31-0) → N-(4-chlorophenyl)-1-methyl-1H-pyrazol-3-amine

Conditions	Yield
With copper(l) iodide; N-(2,6-dimethylphenyl)-6-hydroxypicolinamide; potassium carbonate In dimethyl sulfoxide at 110℃;	99%

2,5-hexanedione (110-13-4) + methyl-1 amino-3 pyrazole (1904-31-0) → 3-(2,5-dimethyl-1H-pyrrol-1-yl)-1-methyl-1H-pyrazole (34605-66-8)

Conditions	Yield
toluene-4-sulfonic acid In toluene for 4h; Reflux;	98%
With acetic acid In toluene at 155℃;	98.1%
With toluene-4-sulfonic acid In benzene at 115℃; for 4h;	94%

methyl-1 amino-3 pyrazole (1904-31-0) → 3-(2,5-dimethyl-1H-pyrrol-1-yl)-1-methyl-1H-pyrazole (34605-66-8)

Conditions	Yield
With acetic acid In toluene at 155℃;	98.1%

1-(2-bromophenyl)pyrazole + methyl-1 amino-3 pyrazole (1904-31-0) → N-(2-(1H-pyrazol-1-yl)phenyl)-1-methyl-1H-pyrazol-3-amine

Conditions	Yield
With copper(l) iodide; N-(2,6-dimethylphenyl)-6-hydroxypicolinamide; potassium carbonate In dimethyl sulfoxide at 110℃;	98%

6-bromo-2-methoxypyridine (40473-07-2) + methyl-1 amino-3 pyrazole (1904-31-0) → 6-methoxy-N-(1-methyl-1H-pyrazol-3-yl)pyridin-2-amine

Conditions	Yield
With copper(l) iodide; N-(2,6-dimethylphenyl)-6-hydroxypicolinamide; potassium carbonate In dimethyl sulfoxide at 110℃;	98%

4-chloro-7-isothiocyanato-7-de(acetamide)colchicine (1267993-72-5) + methyl-1 amino-3 pyrazole (1904-31-0) → 4-chloro-N-[(1-methylpyrazole-3-yl)thiocarbamoyl]deacetyl colchicine (1267992-51-7)

Conditions	Yield
In N,N-dimethyl-formamide at 80℃; for 2h; Inert atmosphere;	96%

methyl-1 amino-3 pyrazole (1904-31-0) → 1-methyl-1H-pyrazole-3-diazonium haxafluorophosphate

Conditions	Yield
With hexafluorophosphoric acid; isopentyl nitrite In methanol at -20℃; for 1h;	95%

5-chloro-2-methylphenylisothiocyanate (19241-36-2) + methyl-1 amino-3 pyrazole (1904-31-0) → 1-(5-chloro-2-methyl-phenyl)-3-(1-methyl-1H-pyrazol-3-yl)-thiourea (221089-29-8)

Conditions	Yield
	95%

(E)-(3-chloro-4-methanesulfonyl-phenyl)-isobutoxyimino-acetic acid (1033780-31-2) + methyl-1 amino-3 pyrazole (1904-31-0) → (E)-2-(3-chloro-4-methanesulfonyl-phenyl)-2-isobutoxyimino-N-(1-methyl-1H-pyrazol-3-yl)-acetamide (1033780-09-4)

Conditions	Yield
Stage #1: (E)-(3-chloro-4-methanesulfonyl-phenyl)-isobutoxyimino-acetic acid; methyl-1 amino-3 pyrazole With N-ethyl-N,N-diisopropylamine; HATU In dichloromethane at 0℃; for 2h; Stage #2: With sodium hydrogencarbonate In water	95%

2-chloro-5-fluoro-4-(3-nitrophenoxy)-7-{[2-(trimethylsilyl)ethoxy]methyl}-7H-pyrrolo[2,3-d]pyrimidine (1428775-55-6) + methyl-1 amino-3 pyrazole (1904-31-0) → 5-fluoro-N-(1-methyl-1H-pyrazol-3-yl)-4-(3-nitrophenoxy)-7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-d]pyrimidin-2-amine (1428775-56-7)

Conditions	Yield
With tris-(dibenzylideneacetone)dipalladium(0); caesium carbonate; 4,5-bis(diphenylphos4,5-bis(diphenylphosphino)-9,9-dimethylxanthenephino)-9,9-dimethylxanthene In 1,4-dioxane at 140℃; for 0.75h; Inert atmosphere; Microwave irradiation;	95%

bis(2,4,6-trichlorophenyl) 2-(3,5-dichlorophenyl)propanedioate + methyl-1 amino-3 pyrazole (1904-31-0) → 6-(3,5-dichlorophenyl)-5-hydroxy-1-methylpyrazolo[1,5-a]pyrimidin-7-one

Conditions	Yield
In toluene for 1h; Reflux;	94%

methyl-1 amino-3 pyrazole (1904-31-0) → 4-iodo-1-methyl-3-amino-1H-pyrazole

Conditions	Yield
With dihydrogen peroxide; iodine In ethanol; water at 15 - 35℃; for 6h;	93.1%

methyl-1 amino-3 pyrazole (1904-31-0) → 5-methylpyrazolodithiazolium chloride (89088-58-4)

Conditions	Yield
With disulfur dichloride In acetic acid 1) 0 deg C to ambient temp. 2) up to 65 deg C, 3h 3) 65 deg C, 2h;	93%

2-(1-((tert-butoxycarbonyl)amino)cyclobutyl)-2-hydroxyacetic acid (1232365-39-7) + methyl-1 amino-3 pyrazole (1904-31-0) → {1-[hydroxy-(1-methyl-1H-pyrazol-3-ylcarbamoyl)methyl]cyclobutyl}carbamic acid tert-butyl ester (1232365-56-8)

Conditions	Yield
Stage #1: 2-(1-((tert-butoxycarbonyl)amino)cyclobutyl)-2-hydroxyacetic acid; methyl-1 amino-3 pyrazole With N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 0℃; for 0.166667h; Stage #2: With HATU In N,N-dimethyl-formamide at 20℃; for 2h;	92%
Stage #1: 2-(1-((tert-butoxycarbonyl)amino)cyclobutyl)-2-hydroxyacetic acid; methyl-1 amino-3 pyrazole With N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 0℃; for 0.166667h; Stage #2: With HATU In N,N-dimethyl-formamide at 20℃; for 2h;	92%

2-(1-(tert-butoxycarbonylamino)-3,3-difluorocyclobutyl)-2-hydroxyacetic acid (1232365-45-5) + methyl-1 amino-3 pyrazole (1904-31-0) → {3,3-difluoro-1-[hydroxy-(1-methyl-1H-pyrazol-3-ylcarbamoyl)methyl]cyclobutyl}carbamic acid tert-butyl ester (1311321-33-1)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine; HATU In N,N-dimethyl-formamide at 0 - 20℃; for 2h;	92%

ethyl (2-chloroaceto)acetate (638-07-3) + methyl-1 amino-3 pyrazole (1904-31-0) → 5-Chloromethyl-1-methyl-1H-pyrazolo[1,5-a]pyrimidin-7-one (104164-03-6)

Conditions	Yield
With PPA at 100℃;	91%

3-[(1S)-2-tert-butoxy-1-methylethoxy]-5-[4-(methylsulfonyl)phenoxy]benzoic acid (883907-39-9) + methyl-1 amino-3 pyrazole (1904-31-0) → 3-[(1S)-2-tert-butoxy-1-methylethoxy]-N-(1-methyl-1H-pyrazol-3-yl)-5-[4-(methylsulfonyl)phenoxy]benzamide (883907-34-4)

Conditions	Yield
Stage #1: 3-[(1S)-2-tert-butoxy-1-methylethoxy]-5-[4-(methylsulfonyl)phenoxy]benzoic acid With 1,1'-carbonyldiimidazole In acetonitrile at 25℃; for 2h; Stage #2: methyl-1 amino-3 pyrazole In acetonitrile at 60℃; for 18h; Product distribution / selectivity;	91%
Stage #1: 3-[(1S)-2-tert-butoxy-1-methylethoxy]-5-[4-(methylsulfonyl)phenoxy]benzoic acid With 1,1'-carbonyldiimidazole In tetrahydrofuran at 20℃; for 1.08333h; Stage #2: methyl-1 amino-3 pyrazole In tetrahydrofuran; toluene at 60℃; for 18h; Product distribution / selectivity;

3-[4-(azetidin-1-ylcarbonyl)phenoxy]-5-[(1S)-2-tert-butoxy-1-methylethoxy]benzoic acid (937842-58-5) + methyl-1 amino-3 pyrazole (1904-31-0) → 3-[4-(Azetidin-1-ylcarbonyl)phenoxy]-5-[(1S)-2-tert-butoxy-1-methylethoxy]-N-(1-methyl-1H-pyrazol-3-yl)benzamide (937842-59-6)

Conditions	Yield
Stage #1: 3-[4-(azetidin-1-ylcarbonyl)phenoxy]-5-[(1S)-2-tert-butoxy-1-methylethoxy]benzoic acid With 4-methyl-morpholine; 2-chloro-4,6-dimethoxy-1 ,3,5-triazine In acetonitrile at 0 - 20℃; for 1.3h; Stage #2: methyl-1 amino-3 pyrazole In acetonitrile at 20℃; for 0.333333h; Product distribution / selectivity;	90%
Stage #1: 3-[4-(azetidin-1-ylcarbonyl)phenoxy]-5-[(1S)-2-tert-butoxy-1-methylethoxy]benzoic acid With 1,1'-carbonyldiimidazole In acetonitrile at 25℃; for 1.08333h; Stage #2: methyl-1 amino-3 pyrazole In acetonitrile at 50℃; Product distribution / selectivity;	89%

methyl-1 amino-3 pyrazole (1904-31-0) → 4-bromo-1-methyl-1H-pyrazol-3-ylamine (146941-72-2)

Conditions	Yield
With bromine In ethanol at 0 - 15℃; for 1h;	89.4%
With sodium hydroxide; bromine In dichloromethane; water

3-bromo-4-methylbenzoic acid (7697-26-9) + methyl-1 amino-3 pyrazole (1904-31-0) → 3 -bromo-4-methyl-N-(1-methyl-1H-pyrazol-3-yl)benzamide

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 15℃; for 12h;	89.2%

ortho-bromophenylacetic acid (18698-97-0) + methyl-1 amino-3 pyrazole (1904-31-0) → 2-(2-bromophenyl)-N-(1-methyl-1H-pyrazol-3-yl)acetamide (1609551-50-9)

Conditions	Yield
Stage #1: ortho-bromophenylacetic acid With oxalyl dichloride In dichloromethane at 0 - 20℃; for 2h; Stage #2: methyl-1 amino-3 pyrazole In dichloromethane at 0 - 20℃;	88%

6-chloro-4-(2-methylpyridin-4-yl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile + methyl-1 amino-3 pyrazole (1904-31-0) → 6-[(1-methyl-1H-pyrazol-3-yl)amino]-4-(2-methylpyridin-4-yl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile

Conditions	Yield
With tris-(dibenzylideneacetone)dipalladium(0); 4,5-bis(diphenylphos4,5-bis(diphenylphosphino)-9,9-dimethylxanthenephino)-9,9-dimethylxanthene; sodium t-butanolate In toluene at 90℃; for 18h; Buchwald-Hartwig Coupling; Inert atmosphere; Sealed tube;	88%

ethyl 4,4,4-trifluoroacetoacetate (372-31-6) + methyl-1 amino-3 pyrazole (1904-31-0) → 4-trifluoromethyl-6-hydroxy-2-methylpyrazolo<3,4-b>pyridine

Conditions	Yield
In acetic acid for 4h; Heating;	87.4%

di(tert-butyl)chlorophosphine (13716-10-4) + methyl-1 amino-3 pyrazole (1904-31-0) → P,P-di(tert-butyl)-N-(1-methyl-1H-pyrazol-3-yl)phosphinous amide (1367863-21-5)

Conditions	Yield
With triethylamine at 125℃; for 72h; Inert atmosphere;	87%

2-[(3-bromo-4-nitrophenoxy)methyl]quinoline + methyl-1 amino-3 pyrazole (1904-31-0) → 1-methyl-N-[2-nitro-5-(quinolin-2-ylmethoxy)phenyl]-1H-pyrazol-3-amine

Conditions	Yield
With tris-(dibenzylideneacetone)dipalladium(0); caesium carbonate; 4,5-bis(diphenylphos4,5-bis(diphenylphosphino)-9,9-dimethylxanthenephino)-9,9-dimethylxanthene In toluene at 85℃; for 2h; Buchwald-Hartwig Coupling; Inert atmosphere;	87%

tert-butyl {3-[(2-chloro-7-{[2-(trimethylsilyl)ethoxy]methyl}-7H-pyrrolo[2,3-d]pyrimidin-4-yl)oxy]phenyl}carbamate (1428775-59-0) + methyl-1 amino-3 pyrazole (1904-31-0) → tert-butyl (3-((2-((1-methyl-1H-pyrazol-3-yl)amino)-7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)oxy)phenyl)carbamate

Conditions	Yield
With tris-(dibenzylideneacetone)dipalladium(0); caesium carbonate; 4,5-bis(diphenylphos4,5-bis(diphenylphosphino)-9,9-dimethylxanthenephino)-9,9-dimethylxanthene In 1,4-dioxane at 140℃; for 0.75h; Buchwald-Hartwig Coupling; Microwave irradiation;	87%

Upstream product

• 54210-32-1 1-methyl-3-nitro-1H-pyrazole 
• 75092-34-1 4-iodo-1-methyl-3-nitro-1H-pyrazole 
• 91027-92-8 N-(1-methyl-3-pyrazolyl)-acetoacetamide 

Downstream Products

• 128883-86-3 tert-butyl (1-methyl-1H-pyrazol-3-yl)carbamate 
• 64748-58-9 5-(4-chloro-phenyl)-1-methyl-1H-pyrazolo[1,5-a]pyrimidin-7-one 
• 97584-37-7 5-(4-Methoxy-phenyl)-1-methyl-1H-pyrazolo[1,5-a]pyrimidin-7-one 
• 151049-87-5 3-bromo-1-methyl-1H-pyrazole 
• 127107-29-3 3-amino-1-methyl-1H-pyrazole hydrochloride 
• 720717-79-3 5-acetyl-2-ethyl-4-((1-methyl-1H-pyrazol-3-yl)amino)-6-phenylpyridazin-3(2H)-one 
• 871657-77-1 3-(benzyloxy)-N-(1-methyl-1H-pyrazol-3-yl)-5-{(1S)-1-methyl-2-[(triisopropylsilyl)oxy]ethoxy}benzamide 
• 871657-56-6 3-(benzyloxy)-5-[(1R)-2-methoxy-1-methylethoxy]-N-(1-methyl-1H-pyrazol-3-yl)benzamide 
• 871656-62-1 3-[((1S)-2-{[(1,1-dimethylethyl)(dimethyl)silyl]oxy}-1-methylethyl)oxy]-N-(1-methyl-1H-pyrazol-3-yl)-5-[(phenylmethyl)oxy]benzamide 
• 221089-29-8 1-(5-chloro-2-methyl-phenyl)-3-(1-methyl-1H-pyrazol-3-yl)-thiourea 
• 64748-43-2 1-methyl-5-phenyl-1H-pyrazolo[1,5-a]pyrimidin-7-one 
• 915771-05-0 N-(1-methyl-1H-pyrazol-3-yl)-3,5-bis[(phenylmethyl)oxy]benzamide 
• 915770-79-5 3-{[2-fluoro-1-(fluoromethyl)ethyl]oxy}-N-(1-methyl-1H-pyrazol-3-yl)-5-[(phenylmethyl)oxy]benzamide 
• 925423-72-9 3-{[4-(azetidin-1-ylcarbonyl)-2-chlorophenyl]oxy}-N-(1-methyl-1H-pyrazol-3-yl)-5-[(phenylmethyl)oxy]benzamide 

Relevant articles and documents

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