37622-90-5

Basic information

• Product Name: Ethyl pyrazole-4-carboxylate
• Synonyms: ETHYL PYRAZOLE-4-CARBOXYLATE;ETHYL 4-PYRAZOLECARBOXYLATE;PYRAZOLE-4-CARBOXYLIC ACID ETHYL ESTER;Ethyl 1H-pyrazole-4-carboxylate;Ethyl 4-pyarazolecarboxylate;Ethyl pyrazole-4-carboxylate 98+%;1H-Pyrazole-4-carboxylicacid,ethylester(9CI);Ethyl 4-pyrazolecarboxylate, 99% - See B25351
• CAS NO: 37622-90-5
• Molecular Formula: C₆H₈N₂O₂
• Molecular Weight: 140.14
• EINECS: 1312995-182-4
• Product Categories: CARBOXYLICESTER;Building Blocks;Heterocyclic Building Blocks;Pyrazoles;Heterocycles;NULL
• Mol File: 37622-90-5.mol
• Article Data: 12

Chemical Properties

• Melting Point: 78-80 °C(lit.)
• Boiling Point: 138-140 °C3 mm Hg(lit.)
• Flash Point: 138-140°C/3mm
• Appearance: White to pale yellow/Crystalline Powder
• Density: 1.2850 (rough estimate)
• Vapor Pressure: 0.00244mmHg at 25°C
• Refractive Index: 1.5010 (estimate)
• Storage Temp.: Sealed in dry,Room Temperature
• Solubility: Miscible with acetone.
• PKA: 11.70±0.50(Predicted)
• CAS DataBase Reference: Ethyl pyrazole-4-carboxylate(CAS DataBase Reference)
• NIST Chemistry Reference: Ethyl pyrazole-4-carboxylate(37622-90-5)
• EPA Substance Registry System: Ethyl pyrazole-4-carboxylate(37622-90-5)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-37/39
• WGK Germany: 3
• HazardClass: IRRITANT
• Hazardous Substances Data: 37622-90-5(Hazardous Substances Data)

Usage

Chemical Properties

White to pale yellow crystalline powder

Uses

Different sources of media describe the Uses of 37622-90-5 differently. You can refer to the following data:
1. Ethyl pyrazole-4-carboxylate is used for the synthesis of isoxazole-4-carboxylic acid derivatives and isoxazole-3,5-dicarboxamides.
2. Used for the synthesis of isoxazole-4-carboxylic acid derivatives and isoxazole-3,5-dicarboxamides as herbicides.

Synthesis Reference(s)

Journal of Heterocyclic Chemistry, 30, p. 865, 1993 DOI: 10.1002/jhet.5570300404

InChI:InChI=1/C6H8N2O2/c1-2-6(9)10-5-3-7-8-4-5/h3-4H,2H2,1H3,(H,7,8)

Synthetic route

3-amino-4-pyrazolecarboxylic acid ethyl ester (6994-25-8) → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With hydrogenchloride; acetic acid; sodium nitrite In ethanol for 1h; Heating;	99%
With hydrogenchloride; acetic acid; sodium nitrite In water at 0℃; for 0.5h;	80 g

ethyl 1H-pyrazole-4-carboxylate hydrochloride → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With sodium hydrogencarbonate In water at 20℃; for 16h;	99%

1H-pyrazole-4-carboxylic acid (37718-11-9) + ethanol (64-17-5) → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With sulfuric acid for 16h; Reflux;	97%
With thionyl chloride at 0 - 20℃; for 3h;	80%
With sulfuric acid

ethyl 2-formyl-3-oxopropanoate (80370-42-9) → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With hydrazine dihydrochloride In ethanol at 0 - 20℃; for 32h;	92%
With hydrazine In ethanol at 0 - 20℃; for 24h;	86%
With hydrazine In ethanol at 0 - 20℃; for 17h;	72.4%
With hydrazine In ethanol at 20℃; for 17h;	72.4%

4-iodopyrazole (3469-69-0) + ethanol (64-17-5) + carbon monoxide (201230-82-2) → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With triethylamine at 100℃; for 4h; Inert atmosphere;	90%

ethyl 1-(hydroxymethyl)-1H-pyrazole-4-carboxylate (112393-66-5) → 4-ethoxycarbonylpyrazole (37622-90-5) + bis(4-ethoxycarbonylpyrazol-1-yl)methane

Conditions	Yield
With potassium fluoride; 18-crown-6 ether; methyl fluorosulfonate In tetrahydrofuran Heating;

sodium-compound of 1H-pyrazole-4-carboxylic acid dioxo-isobutyric acid ethyl ester → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With hydrazine hydrate; acetic acid

ethyl 2-cyanoacetate (105-56-6) → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
Multi-step reaction with 3 steps 1: acetic anhydride / 5 h / 120 °C 2: hydrazine hydrate / ethanol / 8 h / 0 °C 3: sodium nitrite; acetic acid; hydrogenchloride / water / 0.5 h / 0 °C View Scheme

ethyl 2-dichloroacetyl-3-(dimethylamino)acrylate → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
Multi-step reaction with 3 steps 1: toluene / 2 h / -50 °C 2: antimony(III) fluoride / N,N-dimethyl-formamide / 1 h / 90 °C 3: acetic acid; hydrogenchloride / 0.5 h / 0 °C View Scheme

ethyl 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate (141573-95-7) → 4-ethoxycarbonylpyrazole (37622-90-5)

Conditions	Yield
With hydrogenchloride; acetic acid at 0℃; for 0.5h; Reagent/catalyst;

4-ethoxycarbonylpyrazole (37622-90-5) + methyl iodide (74-88-4) → ethyl 1-methylpyrazole-4-carboxylate (85290-80-8)

Conditions	Yield
With caesium carbonate In N,N-dimethyl-formamide at 20℃;	100%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 16h;	85%
Stage #1: 4-ethoxycarbonylpyrazole With sodium hydride In tetrahydrofuran at 25℃; for 1h; Inert atmosphere; Stage #2: methyl iodide In tetrahydrofuran at 60 - 65℃; for 6h;	83%

4-ethoxycarbonylpyrazole (37622-90-5) + (2-bromo-5-methyl-1,3-thiazol-4-yl)methanol (1187836-86-7) → ethyl 1-[(2-bromo-5-methyl-1,3-thiazol-4-yl)methyl]-1H-pyrazole-4-carboxylate (1190235-93-8)

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In tetrahydrofuran at 0℃; for 2h; Inert atmosphere;	100%

4-ethoxycarbonylpyrazole (37622-90-5) + C12H8ClF3S → ethyl 1-({5-[3-(trifluoromethyl)phenyl]thiophen-2-yl}methyl)-1H-pyrazole-4-carboxylate (1190235-28-9)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 70℃;	100%

4-ethoxycarbonylpyrazole (37622-90-5) + p-methoxybenzyl chloride (824-94-2) → 1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylic acid ethyl ester

Conditions	Yield
With potassium carbonate In acetonitrile at 20℃; for 4h; Reflux; Inert atmosphere;	100%
With potassium carbonate In acetonitrile for 4h; Reflux;	100%
In acetonitrile at 20℃; for 4h; Reflux;	99%

4-ethoxycarbonylpyrazole (37622-90-5) + methylamine (74-89-5) → N-methyl-1H-pyrazole-4-carboxamide (1154383-52-4)

Conditions	Yield
In water at 50 - 55℃; for 4h; Inert atmosphere;	100%
In water at 65℃; for 2h;

4-ethoxycarbonylpyrazole (37622-90-5) + 1-(allyloxy)-2-(chloromethyl)benzene (153034-33-4) → ethyl-(2-(allyloxy)benzyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With potassium carbonate In acetonitrile for 6h; Reflux;	100%

4-ethoxycarbonylpyrazole (37622-90-5) + sodium chlorodifluoroacetate (1895-39-2) → ethyl 1-(difluoromethyl)-1H-pyrazole-4-carboxylate (129819-40-5)

Conditions	Yield
With sodium hydrogencarbonate In N,N-dimethyl-formamide at 100℃;	100%
With sodium hydrogencarbonate In N,N-dimethyl-formamide at 100℃; for 40h;

4-ethoxycarbonylpyrazole (37622-90-5) + [3-[N-(tert-butoxycarbonyl)amino]phenyl]methyl bromide (118684-32-5) → ethyl 1-(3-((tert-butoxycarbonyl)amino)benzyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With potassium carbonate In acetone for 3h; Reflux;	100%

4-ethoxycarbonylpyrazole (37622-90-5) + (2-trimethylethylsilylethoxy)methyl chloride (76513-69-4) → ethyl 1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazole-4-carboxylate (1125880-03-6)

Conditions	Yield
Stage #1: 4-ethoxycarbonylpyrazole With sodium hydride In N,N-dimethyl-formamide; mineral oil at 0℃; for 0.25h; Stage #2: (2-trimethylethylsilylethoxy)methyl chloride In N,N-dimethyl-formamide; mineral oil at 0 - 20℃; for 16h;	99.3%
Stage #1: 4-ethoxycarbonylpyrazole With sodium hydride In tetrahydrofuran at 0 - 20℃; for 3h; Inert atmosphere; Stage #2: (2-trimethylethylsilylethoxy)methyl chloride In tetrahydrofuran at 0 - 20℃; for 3h; Inert atmosphere;	98%
With sodium hydride In tetrahydrofuran at 0 - 20℃;	96%

4-ethoxycarbonylpyrazole (37622-90-5) → 3,5-dibromo-1H-pyrazole-4-carboxylic acid ethyl ester (1017802-86-6)

Conditions	Yield
With bromine; sodium acetate In ethanol at 20℃; for 5h;	99%
With bromine; sodium acetate In ethanol; water at 20℃; for 10h;	92%
With bromine; sodium acetate In ethanol at 20℃;

4-ethoxycarbonylpyrazole (37622-90-5) + dimethylamino sulfonyl chloride (13360-57-1) → ethyl 1-(N,N-dimethylsulfamoyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With 1,4-diaza-bicyclo[2.2.2]octane In acetonitrile for 1h; Inert atmosphere;	99%
Stage #1: 4-ethoxycarbonylpyrazole With sodium hydride In tetrahydrofuran; mineral oil at 0℃; for 0.333333h; Inert atmosphere; Stage #2: dimethylamino sulfonyl chloride In tetrahydrofuran; mineral oil at 25℃; for 22h; Inert atmosphere;	91%

4-ethoxycarbonylpyrazole (37622-90-5) + C13H8ClFN2O2 → C19H15FN4O4

Conditions	Yield
With potassium phosphate; tris-(dibenzylideneacetone)dipalladium(0); tert-butyl XPhos In tert-butyl alcohol at 80℃; Inert atmosphere;	99%

4-ethoxycarbonylpyrazole (37622-90-5) + 2-(tert-butyldimethylsilyloxy)ethyl bromide (86864-60-0) → ethyl 1-(2-((tert-butyldimethylsilyl)oxy)ethyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With caesium carbonate In acetonitrile at 20℃; for 16h; Cooling with ice; Inert atmosphere; regioselective reaction;	99%

4-ethoxycarbonylpyrazole (37622-90-5) + (1-bromoethyl)benzne (585-71-7, 38661-81-3) → 1-(1-phenylethyl)-1H-pyrazole-4-carboxylic acid ethyl ester

Conditions	Yield
Stage #1: 4-ethoxycarbonylpyrazole With sodium hydride In N,N-dimethyl-formamide at 0℃; for 0.5h; Stage #2: (1-bromoethyl)benzne In N,N-dimethyl-formamide at 20℃; for 2h;	99%

2-chloro-6-nitro-4-quinazolone (80195-33-1) + 4-ethoxycarbonylpyrazole (37622-90-5) → 1-(6-nitro-4-oxo-3,4-dihydro-quinazolin-2-yl)-1H-pyrazole-4-carboxylic acid ethyl ester (1238692-93-7)

Conditions	Yield
In xylenes at 20 - 130℃; for 19h;	98%

4-ethoxycarbonylpyrazole (37622-90-5) + 2-chloro-1-{4-(3,5-di-tert-butyl-4-hydroxyphenylsulfanyl)-4-[3,5-di-tert-butyl-4-(3-pyrazol-1-ylpropoxy)phenylsulfanyl]-piperidin-1-yl}ethanone (1402049-39-1) → 1-(2-{4-(3,5-di-tert-butyl-4-hydroxyphenylsulfanyl)-4-[3,5-di-tert-butyl-4-(3-pyrazol-1-ylpropoxy)phenylsulfanyl]piperidin-1-yl}-2-oxoethyl)-1H-pyrazole-4-carboxylic acid ethyl ester (1402049-40-4)

Conditions	Yield
Stage #1: 4-ethoxycarbonylpyrazole; 2-chloro-1-{4-(3,5-di-tert-butyl-4-hydroxyphenylsulfanyl)-4-[3,5-di-tert-butyl-4-(3-pyrazol-1-ylpropoxy)phenylsulfanyl]-piperidin-1-yl}ethanone With sodium hydride In tetrahydrofuran; mineral oil at 20℃; for 1h; Stage #2: With ammonium chloride In tetrahydrofuran; mineral oil	98%

4-ethoxycarbonylpyrazole (37622-90-5) + 5-iodo-2-neopentyloxy-benzonitrile → ethyl 1-(3'-cyano-4'-neopentyloxyphenyl)-pyrazol-4-carboxylate (206884-97-1)

Conditions	Yield
With trans-N,N'-dimethyl-1,2-cyclohexyldiamine; copper(l) iodide; potassium carbonate In N,N-dimethyl-formamide at 110℃; for 24h; Inert atmosphere; regioselective reaction;	98%

4-ethoxycarbonylpyrazole (37622-90-5) + 5-bromo-2-(isopropylthio)benzonitrile → ethyl 1-(3-cyano-4-(isopropylthio)phenyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With copper(l) iodide; potassium carbonate In N,N-dimethyl-formamide at 10℃; for 24h; Inert atmosphere;	98%

4-chloromethyl-3,5-dimethylisoxazole (19788-37-5) + 4-ethoxycarbonylpyrazole (37622-90-5) → ethyl 1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazole-4-carboxylate (1119833-53-2)

Conditions	Yield
With caesium carbonate In N,N-dimethyl-formamide at 80℃; for 16h; Inert atmosphere;	97%
With caesium carbonate In N,N-dimethyl-formamide	80%
With caesium carbonate In N,N-dimethyl-formamide at 80℃; for 12h;	80%
With caesium carbonate In N,N-dimethyl-formamide at 80℃; for 12h;	80%

4-ethoxycarbonylpyrazole (37622-90-5) + p-Methoxybenzyl bromide (2746-25-0) → 1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylic acid ethyl ester

Conditions	Yield
With potassium carbonate In acetone at 20 - 50℃; for 17h;	97%
With potassium carbonate In acetone at 20 - 50℃; for 17h;	97%
With potassium carbonate In acetone for 12h; Reflux;

4-ethoxycarbonylpyrazole (37622-90-5) → 1H-pyrazole-4-carbaldehyde (35344-95-7)

Conditions	Yield
With n-butyllithium; diisobutylaluminium hydride; tert-butyl alcohol In tetrahydrofuran; hexane at 0℃;	97%

2-(2-bromoethyl)-2-methyl-1,3-dioxolane (37865-96-6) + 4-ethoxycarbonylpyrazole (37622-90-5) → ethyl 1-(2-(2-methyl-1,3-dioxolan-2-yl)ethyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With caesium carbonate In acetonitrile at 65℃; for 2h; Sealed tube;	97%

4-ethoxycarbonylpyrazole (37622-90-5) + (4-((5-cyclopropyl-3-(2,6-dichlorophenyl)isoxazol-4-yl)methoxy)bicyclo[2.2.2]octan-1-yl)methanol → ethyl 1-((4-((5-cyclopropyl-3-(2,6-dichlorophenyl)isoxazol-4-yl)methoxy)bicyclo[2.2.2]octan-1-yl)methyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With cyanomethylenetributyl-phosphorane In toluene at 100℃; for 6h;	97%

4-ethoxycarbonylpyrazole (37622-90-5) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
With sodium hydroxide In water for 2h; Reflux; Inert atmosphere;	96%

4-ethoxycarbonylpyrazole (37622-90-5) + xanthene (92-83-1) → ethyl 1-(9H-xanthen-9-yl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With dibenzoyl peroxide In 1,2-dichloro-ethane at 80℃; for 6h; Schlenk technique;	96%

4-ethoxycarbonylpyrazole (37622-90-5) + 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione (58-08-2) → triethyl 1,1',1''-(1,3,7-trimethyl-2,6-dioxohexahydro-4H-purine-4,5,8(7H)-triyl)tris(1H-pyrazole-4-carboxylate)

Conditions	Yield
With tetrabutylammonium tetrafluoroborate In acetonitrile at 45℃; for 10h; Inert atmosphere; Electrochemical reaction; Green chemistry; diastereoselective reaction;	96%

4-ethoxycarbonylpyrazole (37622-90-5) + 2-benzyloxy-3-methylbutanoic acid (56972-71-5) → ethyl 1-(1-(benzyloxy)-2-methylpropyl)-1H-pyrazole-4-carboxylate

Conditions	Yield
With 2,4,6-trimethyl-pyridine; tert-butylammonium hexafluorophosphate(V) In dichloromethane for 3h; Molecular sieve; Electrochemical reaction;	96%

Upstream product

• 37718-11-9 1H-pyrazole-4-carboxylic acid 
• 64-17-5 ethanol 
• 80370-42-9 ethyl 2-formyl-3-oxopropanoate 
• 112393-66-5 ethyl 1-(hydroxymethyl)-1H-pyrazole-4-carboxylate 
• 6994-25-8 3-amino-4-pyrazolecarboxylic acid ethyl ester 
• 3469-69-0 4-iodopyrazole 
• 201230-82-2 carbon monoxide 
• 105-56-6 ethyl 2-cyanoacetate 
• 141573-95-7 ethyl 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate 

Downstream Products

• 129819-40-5 ethyl 1-(difluoromethyl)pyrazole-4-carboxylate 
• 129819-41-6 ethyl 1-bromodifluoromethylpyrazole-4-carboxylate 
• 140945-40-0 1-(2-Ethoxyethyl)-2-4-[4-(4-ethyloxycarbonylpyrazol-1-yl)butyl]piperazin-1-ylmethyl benzimidazole 
• 88529-68-4 ethyl 1-(triphenylmethyl)-pyrazole-4-carboxylate 
• 741717-60-2 1-(3'-pyridine)ethyl-4-pyrazolecarboxylate 
• 1245258-67-6 1-(2'-bromophenyl)ethylpyrazole-4-carboxylate 
• 915394-68-2 1-(5-bromo-pyridin-2-yl)-1H-pyrazole-4-carboxylic acid ethyl ester 
• 915715-40-1 1-(5-benzyloxymethyl-1-oxy-pyridin-2-yl)-1H-pyrazole-4-carboxylic acid ethyl ester 
• 150559-94-7 ethyl 1‐benzyl‐1H‐pyrazole‐4‐carboxylate 
• 1044662-17-0 ethyl 1-(3-fluorobenzyl)pyrazole-4-carboxylate 
• 1035224-53-3 ethyl 1-{[3-(trifluoromethyl)phenyl]methyl}-1H-pyrazole-4-carboxylate 
• 782493-64-5 4-(4-ethoxycarbonylpyrazol-1-yl)piperidine-1-carboxylic acid tert-butyl ester 
• 243985-04-8 1-benzoyl-3-(ethoxyoxalyl-amino)-1H-pyrazole-4-carboxylic acid ethyl ester 
• 493035-89-5 [2-(1-benzyl-1H-pyrazol-4-yl)-2-oxo-ethyl]-phosphonic acid dimethyl ester 

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