37718-11-9

Basic information

• Product Name: 4-PYRAZOLECARBOXYLIC ACID
• Synonyms: 1 H-PYRAZOLE-4-CARBOXYLIC ACID;4-PYRAZOLECARBOXYLIC ACID;AKOS PAO-0315;AKOS B015883;ART-CHEM-BB B015883;4-PYRAZOLECARBOXYLIC ACID 97%;Pyrazole-4-carboxylic acid;4-Pyrazolecarboxylic acid,95%
• CAS NO: 37718-11-9
• Molecular Formula: C₄H₄N₂O₂
• Molecular Weight: 112.09
• EINECS: 253-641-5
• Product Categories: Heterocyclic Compounds;Building Blocks;Heterocyclic Building Blocks;Pyrazoles;Heterocycles
• Mol File: 37718-11-9.mol
• Article Data: 5

Chemical Properties

• Melting Point: 282 °C (dec.)(lit.)
• Boiling Point: 417.1 °C at 760 mmHg
• Flash Point: 206.1 °C
• Appearance: Off-white/Powder
• Density: 1.524 g/cm³
• Vapor Pressure: 1.05E-07mmHg at 25°C
• Refractive Index: 1.616
• Storage Temp.: Sealed in dry,Room Temperature
• PKA: 3.81±0.10(Predicted)
• CAS DataBase Reference: 4-PYRAZOLECARBOXYLIC ACID(CAS DataBase Reference)
• NIST Chemistry Reference: 4-PYRAZOLECARBOXYLIC ACID(37718-11-9)
• EPA Substance Registry System: 4-PYRAZOLECARBOXYLIC ACID(37718-11-9)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-37/39
• WGK Germany: 3
• HazardClass: IRRITANT
• Hazardous Substances Data: 37718-11-9(Hazardous Substances Data)

Usage

Chemical Properties

Off-white powder

Uses

Different sources of media describe the Uses of 37718-11-9 differently. You can refer to the following data:
1. 4-Pyrazolecarboxylic acid is used for the synthesis of isoxazole-4-carboxylic acid derivatives and isoxazole-3,5-dicarboxamides
2. 4-Pyrazolecarboxylic acid was used in preparation of ethyl 4-pyrazolecarboxylate.

InChI:InChI=1/C4H4N2O2/c7-4(8)3-1-5-6-2-3/h1-2H,(H,5,6)(H,7,8)

Synthetic route

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%

1-phenyl-2-(4-pyrazolyl)ethanone (96780-98-2) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
With potassium permanganate In water for 0.5h; Heating;	54%
With potassium permanganate In water for 0.5h; Product distribution; Heating;	54%

4-methyl-1H-pyrazole (7554-65-6) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
Stage #1: 4-methyl-1H-pyrazole With sodium hydroxide In water at 60℃; Stage #2: With potassium permanganate In water at 80 - 90℃; for 5h; Stage #3: In water pH=< 2; Acidic conditions;	45%
With potassium permanganate; water

4-bromo-1H-pyrazole (2075-45-8) + phenyllithium (591-51-5) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
anschliessend mit CO2;

4-phenyl-1H-pyrazole (10199-68-5) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
durch Nitrierung,Reduktion des Nitrierungsgemisches und nachfolgende Oxidation mit Permanganat;

1-benzyl-1H-pyrazole-4-carboxylic acid (401647-24-3) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
With ammonia; sodium

4-bromo-1H-pyrazole (2075-45-8) + diethyl ether (60-29-7) + butyl lithium (2 mol) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
anschl. mit CO2 bei -70grad;

pyrazole-tricarboxylic acid-(3.4.5) → NH-pyrazole (288-13-1) + 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
bei schnellem Erhitzen;

4-bromo-1H-pyrazole (2075-45-8) + diethyl ether (60-29-7) + butyl lithium (1 mol) → 1H-pyrazole-4-carboxylic acid (37718-11-9) + 4-bromo-1H-pyrazole-5-carboxylic acid

Conditions	Yield
anschl. mit CO2 bei -70grad;

4-bromo-1H-pyrazole (2075-45-8) → 1H-pyrazole-4-carboxylic acid (37718-11-9)

Conditions	Yield
With hydrogenchloride; n-butyllithium In hexane; water

1H-pyrazole-4-carboxylic acid (37718-11-9) + 6-chloro-N4-methylpyridine-3,4-diamine (87034-76-2) → 6-chloro-1-methyl-2-(1H-pyrazol-4-yl)-1H-imidazo[4,5-c]pyridine (1612171-92-2)

Conditions	Yield
With polyphosphoric acid at 150℃; for 18h; Inert atmosphere; Sealed tube;	100%

1H-pyrazole-4-carboxylic acid (37718-11-9) + 6-bromopyridine-3,4-diamine (1033203-41-6) → 6-bromo-2-(1H-pyrazol-4-yl)-3H-imidazo[4.5-c]pyridine (1612171-97-7)

Conditions	Yield
With polyphosphoric acid at 200℃; for 18h;	100%

1H-pyrazole-4-carboxylic acid (37718-11-9) + 6-bromopyridine-3,4-diamine (1033203-41-6) → 6-bromo-2-(1H-pyrazol-4-yl)-3H-imidazo[4,5-c]pyridine

Conditions	Yield
With polyphosphoric acid at 200℃; for 18h; Sealed tube;	100%

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

1H-pyrazole-4-carboxylic acid (37718-11-9) → 1H-pyrazole-4-carboxylic acid chloride (103286-53-9)

Conditions	Yield
With thionyl chloride for 18h; Heating / reflux;	97%
With thionyl chloride for 18h; Reflux;	97%
With thionyl chloride at 85℃; Inert atmosphere;	91%

1H-pyrazole-4-carboxylic acid (37718-11-9) + N-methoxylamine hydrochloride (593-56-6) → N-methoxy-1H-pyrazole-4-carboxamide

Conditions	Yield
Stage #1: 1H-pyrazole-4-carboxylic acid With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In N,N-dimethyl-formamide at 20℃; for 0.166667h; Inert atmosphere; Stage #2: N-methoxylamine hydrochloride With N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃; for 16h; Inert atmosphere;	94%

methanol (67-56-1) + 1H-pyrazole-4-carboxylic acid (37718-11-9) → methyl pyrazole-4-carboxylate (51105-90-9)

Conditions	Yield
With sulfuric acid at 0 - 80℃; for 16h;	93.32%
With sulfuric acid at 70℃; for 20h;	78%
With hydrogenchloride at 10 - 35℃;	5 g
With sulfuric acid at 0℃; Reflux;	4.5 g

1H-pyrazole-4-carboxylic acid (37718-11-9) + 6-bromo-N3-methylpyridine-3,4-diamine (1218997-22-8) → 6-bromo-3-methyl-2-(1H-pyrazol-4-yl)-3H-imidazo[4,5-c]pyridine (1612172-01-6)

Conditions	Yield
With polyphosphoric acid at 200℃; for 5h; Sealed tube;	93%

1H-pyrazole-4-carboxylic acid (37718-11-9) + tert-butyl 4-(aminomethyl)benzylcarbamate (108468-00-4) → (4-{[(1H-pyrazole-4-carbonyl)amino]methyl}benzyl)carbamic acid tert-butyl ester (1618648-11-5)

Conditions	Yield
With benzotriazol-1-ol; triethylamine In dichloromethane; N,N-dimethyl-formamide at 0 - 20℃; for 18h; Inert atmosphere;	93%

3,4-dihydro-2H-pyran (110-87-2) + 1H-pyrazole-4-carboxylic acid (37718-11-9) → 1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carboxylic acid (848818-59-7)

Conditions	Yield
With toluene-4-sulfonic acid In ethyl acetate; N,N-dimethyl-formamide at 20℃; for 16h;	91%
With toluene-4-sulfonic acid In DMF (N,N-dimethyl-formamide); ethyl acetate at 20℃; for 3h;	90%
With toluene-4-sulfonic acid In N,N-dimethyl-formamide at 20℃; for 20h;	70%

1H-pyrazole-4-carboxylic acid (37718-11-9) + 3,4-dichlorobenzyl bromide (18880-04-1) → ethyl 1-(3,4-dichlorobenzyl)-1H-pyrazole-4-carboxylate (1035224-45-3)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃;	91%

1H-pyrazole-4-carboxylic acid (37718-11-9) + copper(II) nitrate trihydrate + aluminium(III) chloride hexahydrate → [Al3(μ3-O)(OH)3][Cu3(μ3-O)(μ-1H-pyrazole-4-carboxylate)3(H2O)6]2

Conditions	Yield
Stage #1: 1H-pyrazole-4-carboxylic acid; copper(II) nitrate trihydrate; aluminium(III) chloride hexahydrate With trifluoroacetic acid In N,N-dimethyl-formamide at 100℃; for 10h; Stage #2: at 150℃; for 12h;	91%

1H-pyrazole-4-carboxylic acid (37718-11-9) + N,N-dimethyl-2-(2-neopentyl-5-(piperidin-4-ylmethylsulfonyl)-1H-benzoimidazol-1-yl)ethanamine (1236007-46-7) → (4-((1-(2-(dimethylamino)ethyl)-2-neopentyl-1H-benzoimidazol-5-ylsulfonyl)methyl)piperidin-1-yl)(1H-pyrazol-4-yl)methanone (1236006-89-5)

Conditions	Yield
With O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; triethylamine In dichloromethane at 18 - 25℃; for 2h;	90%

1H-pyrazole-4-carboxylic acid (37718-11-9) + (R)-2-(4-bromophenyl)-2-cyclopropyl-N′-hydroxypropanimidamide (1360551-95-6) → 3-[(R)-1-(4-bromo-phenyl)-1-cyclopropyl-ethyl]-5-(1H-pyrazol-4-yl)-[1,2,4]oxadiazole (1360552-35-7)

Conditions	Yield
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In 1-methyl-pyrrolidin-2-one at 50℃; for 0.5h; Inert atmosphere; Stage #2: (R)-2-(4-bromophenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In 1-methyl-pyrrolidin-2-one at 100℃; for 16h; Inert atmosphere;	90%
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In 1,4-dioxane at 55℃; for 0.5h; Stage #2: (R)-2-(4-bromophenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In 1,4-dioxane at 120℃; for 18h;
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In 1,4-dioxane at 55℃; for 0.5h; Sealed tube; Stage #2: (R)-2-(4-bromophenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In 1,4-dioxane at 120℃; for 18h; Sealed tube;	1.3 g

1H-pyrazole-4-carboxylic acid (37718-11-9) + copper(II) nitrate trihydrate + zinc(II) nitrate hexahydrate + terephthalic acid (100-21-0) → 4C12H6Cu3N6O6(3-)*2H6O4Zn*12Zn(2+)*3O(2-)*3C8H4O4(2-)

Conditions	Yield
With 1-methyl-pyrrolidin-2-one In N,N-dimethyl-formamide at 100℃; for 12h; Sealed tube;	90%

1H-pyrazole-4-carboxylic acid (37718-11-9) + ammonium hydroxide (1336-21-6) + zinc(II) nitrate (10196-18-6) → (ammonium)[Zn3(OH)(1H-pyrazole-4-carboxylic acid)3]

Conditions	Yield
In methanol; water; N,N-dimethyl-formamide for 6h; Reflux;	90%

1H-pyrazole-4-carboxylic acid (37718-11-9) + copper(II) nitrate trihydrate + zinc(II) nitrate hexahydrate → 6C12H6Cu3N6O6(3-)*6H6O4Zn*20Zn(2+)*5O(2-)*6C4H2N2O2(2-)

Conditions	Yield
With 1-methyl-pyrrolidin-2-one In N,N-dimethyl-formamide at 85℃; for 72h; Sealed tube;	88%

1H-pyrazole-4-carboxylic acid (37718-11-9) + 2-chloro-4-[(1r,3r)-3-amino-2,2,4,4-tetramethylcyclobutoxy]benzonitrile → C19H21ClN4O2

Conditions	Yield
With N-ethyl-N,N-diisopropylamine; N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate In N,N-dimethyl-formamide at 20℃; for 0.5h;	88%

1H-pyrazole-4-carboxylic acid (37718-11-9) + water (7732-18-5) + nickel(II) acetate tetrahydrate (6018-89-9) + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → 8Ni(2+)*12H2O*4HO(1-)*6C4H2N2O2(2-)*4.5C3H7NO

Conditions	Yield
for 6h; Reflux;	86%

1H-pyrazole-4-carboxylic acid (37718-11-9) + (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N'-hydroxypropanimidamide → 5-(4-{(R)-1-cyclopropyl-1-[5-(1H-pyrazol-4-yl)-[1,2,4]oxadiazol-3-yl]ethyl}phenyl)pyrimidin-2-ylamine (1360549-37-6)

Conditions	Yield
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In tetrahydrofuran; N,N-dimethyl-formamide at 50 - 55℃; for 0.5h; Large scale; Stage #2: (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N'-hydroxypropanimidamide In N,N-dimethyl-formamide at 105℃; Large scale;	86%

1H-pyrazole-4-carboxylic acid (37718-11-9) + (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N′-hydroxypropanimidamide (1360552-09-5) → 5-(4-{(R)-1-cyclopropyl-1-[5-(1H-pyrazol-4-yl)-[1,2,4]oxadiazol-3-yl]ethyl}phenyl)pyrimidin-2-ylamine (1360549-37-6)

Conditions	Yield
Stage #1: 1H-pyrazole-4-carboxylic acid With Carbonyldiimidazole In tetrahydrofuran; N,N-dimethyl-formamide at 50℃; for 1h; Inert atmosphere; Stage #2: (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In tetrahydrofuran; N,N-dimethyl-formamide at 105℃; for 17h; Inert atmosphere;	85.9%
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In 1-methyl-pyrrolidin-2-one at 50℃; for 0.5h; Inert atmosphere; Stage #2: (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In 1-methyl-pyrrolidin-2-one at 100℃; for 16h; Inert atmosphere;	82%
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In tetrahydrofuran at 20 - 50℃; for 0.5h; Stage #2: (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In tetrahydrofuran for 24h; Reflux; Stage #3: With acetic acid at 90℃; for 2h;
Stage #1: 1H-pyrazole-4-carboxylic acid With 1,1'-carbonyldiimidazole In tetrahydrofuran at 20 - 50℃; for 0.5h; Stage #2: (R,Z)-2-(4-(2-aminopyrimidin-5-yl)phenyl)-2-cyclopropyl-N′-hydroxypropanimidamide In tetrahydrofuran for 24h; Reflux; Stage #3: With acetic acid at 20 - 90℃; for 2h;	14.7 g

1H-pyrazole-4-carboxylic acid (37718-11-9) + diethyl cyanophosphonate (2942-58-7) + 3-[4-(piperidinomethyl)pyrid-2-yloxy]prop-1-ylamine (88443-62-3) → N-[3-(4-Piperidinomethyl-2-pyridyloxy)propyl]-pyrazole-4-carboxamide

Conditions	Yield
With sodium chloride; sodium hydrogencarbonate; triethylamine In N-methyl-acetamide	85%

1H-pyrazole-4-carboxylic acid (37718-11-9) + 4-(aminomethyl)-1-methyl-5,6,7,8-tetrahydroisoquinolin-3(2H)-one → N-((1-methyl-3-oxo-2,3,5,6,7,8-hexahydroisoquinolin-4-yl)methyl)-1H-pyrazole-4-carboxamide

Conditions	Yield
Stage #1: 1H-pyrazole-4-carboxylic acid With 4-methyl-morpholine; benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 20℃; for 0.5h; Stage #2: 4-(aminomethyl)-1-methyl-5,6,7,8-tetrahydroisoquinolin-3(2H)-one In dichloromethane at 20℃; for 7h;	84%

1H-pyrazole-4-carboxylic acid (37718-11-9) + copper(II) nitrate trihydrate + zinc(II) nitrate hexahydrate + 2,6-Naphthalenedicarboxylic acid (1141-38-4) → 4C12H6Cu3N6O6(3-)*4H6O4Zn*12Zn(2+)*3O(2-)*C4H2N2O2(2-)*2C12H6O4(2-)

Conditions	Yield
In N,N-dimethyl acetamide at 100℃; for 16h; Sealed tube;	83%

1H-pyrazole-4-carboxylic acid (37718-11-9) + copper(II) nitrate trihydrate + zinc(II) nitrate hexahydrate → 3C12H6Cu3N6O6(3-)*H5O4Zn(1-)*6Zn(2+)*C4H2N2O2(2-)

Conditions	Yield
In N,N-dimethyl acetamide at 85℃; for 72h; Sealed tube;	82%

1H-pyrazole-4-carboxylic acid (37718-11-9) + ethyl vinyl ether (109-92-2) → C8H12N2O3

Conditions	Yield
With hydrogenchloride In water; N,N-dimethyl-formamide at 40℃; for 2h;	82%

1H-pyrazole-4-carboxylic acid (37718-11-9) + 2-amino-benzenethiol (137-07-5) → 2-(1H-pyrazol-4-yl)benzo[d]thiazole (40142-85-6)

Conditions	Yield
With 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphinane-2,4,6-trioxide; N-ethyl-N,N-diisopropylamine In ethyl acetate at 100℃; for 0.166667h; Microwave irradiation; Sealed tube;	81%

1H-pyrazole-4-carboxylic acid (37718-11-9) → methyl pyrazole-4-carboxylate (51105-90-9)

Conditions	Yield
With hydrogenchloride In methanol; water	79.6%
With sulfuric acid; sodium methylate In methanol; chloroform

1H-pyrazole-4-carboxylic acid (37718-11-9) + copper(II) nitrate trihydrate + zinc(II) nitrate hexahydrate + terephthalic acid (100-21-0) + 2,6-Naphthalenedicarboxylic acid (1141-38-4) → 12C4H2N2O2(2-)*2C8H4O4(2-)*C12H6O4(2-)*12Cu(1+)*12Zn(2+)*3O(2-)

Conditions	Yield
In 1-methyl-pyrrolidin-2-one; N,N-dimethyl-formamide at 100℃; for 16h;	79%

Upstream product

• 2075-45-8 4-bromo-1H-pyrazole 
• 591-51-5 phenyllithium 
• 37622-90-5 4-ethoxycarbonylpyrazole 
• 60-29-7 diethyl ether 
• 96780-98-2 1-phenyl-2-(4-pyrazolyl)ethanone 
• 401647-24-3 1-benzyl-1H-pyrazole-4-carboxylic acid 
• 10199-68-5 4-phenyl-1H-pyrazole 
• 7554-65-6 4-methyl-1H-pyrazole 

Downstream Products

• 37622-90-5 4-ethoxycarbonylpyrazole 
• 288-13-1 NH-pyrazole 
• 51105-90-9 methyl pyrazole-4-carboxylate 
• 87551-45-9 1H-pyrazole-4-carbohydrazide 
• 141178-50-9 dimethylethyl 3-(1H)-pyrazolecarboxylate 
• 1428926-26-4 N-[4-[[3-[[5-(trifluoromethyl)-2-pyridyl]oxy]phenyl] methylene]cyclohexyl]-1H-pyrazole-4-carboxamide 
• 1360549-37-6 5-(4-{(R)-1-cyclopropyl-1-[5-(1H-pyrazol-4-yl)-[1,2,4]oxadiazol-3-yl]ethyl}phenyl)pyrimidin-2-ylamine 

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