5-Hydroxy-1-methylpyrazole supplier

Name
5-Hydroxy-1-methylpyrazole
EINECS
CAS No. 33641-15-5
Article Data16
CAS DataBase
Density 1.229 g/cm³
Solubility
Melting Point 110-114 °C
Formula C₄H₆N₂O
Boiling Point 217.662 °C at 760 mmHg
Molecular Weight 98.1044
Flash Point 85.439 °C
Transport Information
Appearance
Safety 26-39
Risk Codes 22-37/38-41
Molecular Structure
Hazard Symbols
Synonyms Pyrazol-5-ol,1-methyl- (8CI);1-Methyl-1H-pyrazol-5-ol;1-Methyl-5-hydroxy-1H-pyrazole;1-Methyl-5-hydroxypyrazole;5-Hydroxy-1-methyl-5-pyrazole;1H-Pyrazol-5-ol,1-methyl-;
PSA 38.05000
LogP 0.12570

Synthetic route

: 88398-78-1
1-methyl-5-hydroxypyrazol-4-carboxylic acid ethyl ester

: 33641-15-5
1-methyl-5-hydroxypyrazole

Conditions

Conditions	Yield
Stage #1: 1-methyl-5-hydroxypyrazol-4-carboxylic acid ethyl ester With sodium hydroxide In water at 40℃; for 3h; Stage #2: With hydrogenchloride for 3h; Reflux;	98%
at 120℃; for 6h; Temperature;

: 34846-90-7
methyl 3-methoxyprop-2-enoate

: 60-34-4
methylhydrazine

: 33641-15-5
1-methyl-5-hydroxypyrazole

Conditions

Conditions	Yield
In methanol at 0℃; for 4.66667h; Heating / reflux;	73%
In water at 10℃; Temperature;	69.6%
In methanol for 8h; Reflux; Inert atmosphere;
In methanol; water for 2h; Cooling with ice;

aqueous monomethylhydrazine: aqueous monomethylhydrazine

: 75945-54-9
β-isobutoxyacryl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

Conditions

Conditions	Yield
With hydrogenchloride; triethylamine In tetrahydrofuran

: 5788-17-0
methyl (2E)-3-methoxy-2-propenoate

: 60-34-4
methylhydrazine

: 33641-15-5
1-methyl-5-hydroxypyrazole

Conditions

Conditions	Yield
In methanol at 90℃; for 12 - 18h;

: 623-43-8, 4358-59-2, 18707-60-3, 130981-57-6
methyl crotonate

: 60-34-4
methylhydrazine

: 33641-15-5
1-methyl-5-hydroxypyrazole

Conditions

Conditions	Yield
In methanol for 16h; Reflux; Inert atmosphere;

: C6H8N2O3

: 33641-15-5
1-methyl-5-hydroxypyrazole

Conditions

Conditions	Yield
With sulfuric acid at 65℃; for 8h; Temperature;	18.6 g

: 123-91-1
1,4-dioxane

: 247922-29-8
3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 210631-68-8
topramezone

Conditions

Conditions	Yield
With carbon monoxide; potassium carbonate; triethylamine; triphenylphosphine; palladium(II) chloride In water	100%
With hydrogenchloride; potassium carbonate; triethylamine; bis(triphenylphosphine)palladium(II) dichloride In water

...Expand

: 110964-80-2
4-methylsulphonyl-2-nitrobenzoyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: (1-methyl-5-hydroxypyrazol-4-yl)-(4-methanesulfonyl-2-nitrophenyl)methanone

Conditions

Conditions	Yield
With triethylamine In 1,4-dioxane at 5 - 40℃; for 2h;	96%

: 1196958-18-5
2-methyl-3-ethylsulfinyl-4-methylsulfonylbenzoic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1196958-05-0
[3-(ethylsulfinyl)-2-methyl-4-(methylsulfonyl)phenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone

Conditions

Conditions	Yield
With pyridine; thionyl chloride In ethyl acetate at -25 - 0℃; Inert atmosphere;	91%

: 1070761-73-7
2-methyl-3-(methylsulfinyl)-4-(trifluoromethyl)benzoic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1070761-52-2
(5-hydroxy-1-methyl-1H-pyrazol-4-yl)[2-methyl-3-(methyl-sulfinyl)-4-(trifluoromethyl)phenyl]methanone

Conditions

Conditions	Yield
With pyridine; thionyl chloride In ethyl acetate at -25 - 0℃; Inert atmosphere;	90.7%

: 98-59-9
p-toluenesulfonyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1-methyl-1H-pyrazol-5-yl tosylate

Conditions

Conditions	Yield
With sodium hydroxide In tetrahydrofuran; water at 0 - 20℃; for 2h; Green chemistry;	88%

: 2-chloro-3-fluoro-4-trifluoromethylbenzoyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: (2-chloro-3-fluoro-4-trifluoromethylphenyl)(5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone

Conditions

Conditions	Yield
With triethylamine In 1,2-dichloro-ethane at -5 - 20℃;	86.9%

: 1262652-20-9
2-methoxy-3-methylsulfinyl-4-trifluoromethylbenzoic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1262671-11-3
(5-hydroxy-1-methyl-1H-pyrazol-4-yl)[2-methoxy-3-(methylsulfinyl)-4-(trifluoromethyl)phenyl]methanone

Conditions

Conditions	Yield
With thionyl chloride; 3-Methylpyridine In ethyl acetate at -25 - -20℃; Product distribution / selectivity; Inert atmosphere;	86.5%

: 89-75-8
2,4-dichlorobenzoyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 91436-74-7
1-methyl-5-(2,4-dichlorobenzoyloxy)-pyrazole

Conditions

Conditions	Yield
With sodium hydroxide In chloroform	86%

: 247922-29-8
3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole

: 2597-44-6
formyl radical

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 210631-68-8
topramezone

Conditions

Conditions	Yield
Stage #1: 3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole With potassium carbonate In 1,4-dioxane Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triphenylphosphine; sodium iodide In 1,4-dioxane at 60℃; for 0.5h; Stage #3: formyl radical With palladium on activated charcoal In 1,4-dioxane at 120℃; under 11251.1 Torr; for 20h; Reagent/catalyst; Temperature;	84.4%

...Expand

: 223646-24-0
3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 210631-68-8
topramezone

Conditions

Conditions	Yield
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With pyridine; thionyl chloride In benzene for 3h; Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In 1,4-dioxane at 20℃; for 3h; Stage #3: With potassium carbonate for 6h; Reflux;	81.46%
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With pyridine; thionyl chloride In toluene for 3h; Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In 1,4-dioxane at 20℃; for 3h;	80.5%
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With thionyl chloride for 2h; Reflux; Stage #2: With triethylamine In 1,2-dichloro-ethane at 20 - 30℃; for 0.5h; Stage #3: 1-methyl-5-hydroxypyrazole In 1,2-dichloro-ethane for 4h; Reflux;	20.87%

: 832-53-1
pentafluorobenzenesulonyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1-methyl-1H-pyrazol-5-yl 2,3,4,5,6-pentafluorobenzenesulfonate

Conditions

Conditions	Yield
With triethylamine In dichloromethane at 0 - 20℃;	81%

: 247922-29-8
3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole

: 201230-82-2
carbon monoxide

: 33641-15-5
1-methyl-5-hydroxypyrazole

: [3-(4,5-dihydro-1,2-oxazol-3-yl)-4-mesyl-o-tolyl](5-hydroxy-1-methylpyrazol-4-yl)methanone

Conditions

Conditions	Yield
With potassium carbonate; triethylamine; triphenylphosphine; palladium dichloride In 1,4-dioxane at 120℃; under 4125.41 - 4875.49 Torr; for 40h; Autoclave;	81%

...Expand

: C18H16N2O5

: 33641-15-5
1-methyl-5-hydroxypyrazole

: C22H20N4O5

Conditions

Conditions	Yield
Stage #1: C18H16N2O5 With thionyl chloride In tetrahydrofuran at 20 - 80℃; for 1.5h; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In dichloromethane for 0.5h;	80%

: 68-12-2, 33513-42-7
N,N-dimethyl-formamide

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 117007-77-9
5-chloro-1-methyl-1H-pyrazole-4-carbaldehyde

Conditions

Conditions	Yield
Stage #1: N,N-dimethyl-formamide; 1-methyl-5-hydroxypyrazole With trichlorophosphate at 80℃; for 6.16667h; Stage #2: With sodium hydrogencarbonate In water	77%
With trichlorophosphate In methanol at 0 - 80℃; for 7h; Inert atmosphere;	12.87 g
With trichlorophosphate at 0 - 80℃; for 12h; Inert atmosphere;	16.31 g

: 223646-24-0
3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: [3-(4,5-dihydro-1,2-oxazol-3-yl)-4-mesyl-o-tolyl](5-hydroxy-1-methylpyrazol-4-yl)methanone

Conditions

Conditions	Yield
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With thionyl chloride for 3h; Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In tetrahydrofuran at 20℃; for 3h; Stage #3: With potassium carbonate In tetrahydrofuran for 2h; Reflux;	76.2%

: 124-63-0
methanesulfonyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1-methylpyrazole-5-yl methanesulfonate

Conditions

Conditions	Yield
With triethylamine In ethyl acetate at 0 - 20℃; for 0.166667h; Green chemistry;	74%
With triethylamine In tetrahydrofuran at 0℃; for 2h;	7.04 g

: 420-37-1
trimethoxonium tetrafluoroborate

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 3514-11-2
1,2-dimethyl-1,2-dihydropyrazol-3-on

Conditions

Conditions	Yield
In nitromethane at 20℃; for 24h;	71%

: 824-94-2
p-methoxybenzyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

A: 1-(4-Methoxy-benzyl)-2-methyl-1,2-dihydro-pyrazol-3-one

B: 5-(4-Methoxy-benzyloxy)-1-methyl-1H-pyrazole

Conditions

Conditions	Yield
In methanol at 20℃; for 24h;	A 70% B 5%

...Expand

: 293312-46-6
9-methoxy-6-chloroformyl-3a,4-dihydro-3H-chromeno[4,3-c]isoxazoline

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 293312-16-0
(5-hydroxy-1-methyl-1H-pyrazol-4-yl)-(9-methoxy-3a,4-dihydro-3H-chromeno[4,3-c]isoxazolin-6-yl)methanone

Conditions

Conditions	Yield
Stage #1: 9-methoxy-6-chloroformyl-3a,4-dihydro-3H-chromeno[4,3-c]isoxazoline; 1-methyl-5-hydroxypyrazole With trimethylamine In acetonitrile at 0 - 20℃; Stage #2: With potassium carbonate In 1,4-dioxane for 7h; Heating / reflux;	68%

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 100-51-6
benzyl alcohol

: 5-(benzyloxy)-1-methyl-1H-pyrazole

Conditions

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In tetrahydrofuran at -60 - -30℃; for 19h;	66%

: 3-(2-fluoro-4-methylphenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1-methyl-1H-pyrazol-5-yl 3-(2-fluoro-4-methylphenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate

Conditions

Conditions	Yield
Stage #1: 3-(2-fluoro-4-methylphenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylic acid With dicyclohexyl-carbodiimide In dichloromethane at 20℃; for 1h; Stage #2: 1-methyl-5-hydroxypyrazole With dmap In dichloromethane at 20℃;	65%

: 76513-69-4
(2-trimethylethylsilylethoxy)methyl chloride

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 2-methyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1,2-dihydro-3H-pyrazol-3-one

Conditions

Conditions	Yield
Stage #1: 1-methyl-5-hydroxypyrazole With potassium carbonate In acetonitrile at 20℃; for 0.5h; Stage #2: (2-trimethylethylsilylethoxy)methyl chloride In acetonitrile at 20℃; for 14h;	63%
With potassium carbonate In acetonitrile at 20℃; for 16h;	10 g

: 3998-90-1
2-chloro-6-methyl-isonicotinic acid methyl ester

: 33641-15-5
1-methyl-5-hydroxypyrazole

: methyl 2-(5-hydroxy-1-methyl-1H-pyrazol-4-yl)-6-methylisonicotinate hydrochloride

Conditions

Conditions	Yield
With dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II)*CH2Cl2; sodium carbonate at 130℃; for 16h; Inert atmosphere;	61%

: 3-(4-chloro-2-methylphenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1-methyl-1H-pyrazol-5-yl 3-(4-chloro-2-methylphenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate

Conditions

Conditions	Yield
Stage #1: 3-(4-chloro-2-methylphenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylic acid With dicyclohexyl-carbodiimide In dichloromethane at 20℃; for 1h; Stage #2: 1-methyl-5-hydroxypyrazole With dmap In dichloromethane at 20℃;	60%

: 6-amino-5-chloro-2-(4-chloro-2-fluoro-3-methoxyphenyl)-pyrimidine-4-carboxylic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: C16H12Cl2FN5O3

Conditions

Conditions	Yield
With benzotriazol-1-yloxyl-tris-(pyrrolidino)-phosphonium hexafluorophosphate; triethylamine In dichloromethane at 25℃; for 4h;	59%

: 1207343-99-4
2-chloro-4-methoxy-3-(1-oxothianylideneamino)benzoic acid

: 75-86-5
2-hydroxy-2-methylpropanenitrile

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1207341-28-3
2-chloro-1-[(5-hydroxy-1-methylpyrazole-4-yl)carbonyl]-4-methoxy-3-(1-oxothianylideneamino)benzene

Conditions

Conditions	Yield
Stage #1: 2-chloro-4-methoxy-3-(1-oxothianylideneamino)benzoic acid With 1,1'-carbonyldiimidazole In chloroform at 20℃; for 1h; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In chloroform for 1h; Reflux; Stage #3: 2-hydroxy-2-methylpropanenitrile With triethylamine In acetonitrile at 20℃;	55%

...Expand

: 3-(4-chlorophenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylic acid

: 33641-15-5
1-methyl-5-hydroxypyrazole

: 1-methyl-1H-pyrazol-5-yl 3-(4-chlorophenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate

Conditions

Conditions	Yield
Stage #1: 3-(4-chlorophenyl)-2-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylic acid With dicyclohexyl-carbodiimide In dichloromethane at 20℃; for 1h; Stage #2: 1-methyl-5-hydroxypyrazole With dmap In dichloromethane at 20℃;	53%

5-Hydroxy-1-methylpyrazole Chemical Properties

Systematic Name: 1-Methyl-1H-pyrazol-5-ol
SMILES: Oc1ccnn1C
InChI: InChI=1/C4H6N2O/c1-6-4(7)2-3-5-6/h2-3,7H,1H3
InChIKey: CMXOTACIOGGSNH-UHFFFAOYAF
Empirical Formula: C₄H₆N₂O
Molecular Weight: 98.1032
Product Categories: Heterocyclic Compounds
Index of Refraction: 1.568
Molar Refractivity: 26.102 cm³
Molar Volume: 79.836 cm³
Surface Tension: 44.34 dyne/cm
Density: 1.229 g/cm³
Flash Point: 85.439 °C
Enthalpy of Vaporization: 47.253 kJ/mol
Boiling Point: 217.662 °C at 760 mmHg
Vapour Pressure: 0.089 mmHg at 25 °C
Melting Point of 5-Hydroxy-1-methylpyrazole (CAS NO.33641-15-5): 110-114 °C

5-Hydroxy-1-methylpyrazole Safety Profile

Hazard Codes: Harmful Xn
Risk Statements: 22-37/38-41
R22:Harmful if swallowed.
R37/38:Irritating to respiratory system and skin.
R41:Risk of serious damage to the eyes.
Safety Statements: 26-39
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
S39:Wear eye / face protection.

5-Hydroxy-1-methylpyrazole Specification

5-Hydroxy-1-methylpyrazole (CAS NO.33641-15-5), its Synonyms are Pyrazol-5-ol,1-methyl- (8CI) ; 1-Methyl-5-hydroxy-1H-pyrazole ; 1-Methyl-1H-pyrazol-5-ol ; 1-Methyl-5-hydroxy-1H-pyrazole ; 5-Hydroxy-1-methyl-5-pyrazole ; 1H-Pyrazol-5-ol,1-methyl- .

Product Name

5-Hydroxy-1-methylpyrazole

Synthetic route

5-Hydroxy-1-methylpyrazole Chemical Properties

5-Hydroxy-1-methylpyrazole Safety Profile

5-Hydroxy-1-methylpyrazole Specification

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