6629-60-3

Usage

Uses

Used in Pharmaceutical Industry:
ETHYL HYDRAZINE OXALATE is used as a synthetic intermediate for the production of various pharmaceutical compounds. Its ability to react with different reagents allows for the creation of a wide range of therapeutic agents.
Used in Chemical Synthesis:
ETHYL HYDRAZINE OXALATE is used as a key building block in the synthesis of several chemical compounds, including:
1. 1-ethyl-1H-indazoles: These compounds have potential applications in various fields, such as pharmaceuticals and materials science, due to their unique chemical properties.
2. 3-substituted 1-ethyl-6-methylpyrimido[4,5-c]pyridazine-5,7(1H,6H)-dione derivatives: These complex molecules can be used in the development of new drugs and other advanced materials.
3. 4-(2-alkyl-5-methyl-2H-pyrazol-3-yl)-piperidines: These compounds may have potential applications in the pharmaceutical industry, particularly in the development of new drugs with novel therapeutic properties.

InChI:InChI=1/C2H8N2.C2H2O4/c1-2-4-3;3-1(4)2(5)6/h4H,2-3H2,1H3;(H,3,4)(H,5,6)

Synthetic route

ethylhydrazine oxalic acid salt (6629-60-3) + 2,2-dimethyl-5-(1-hydroxy-3-oxobutylidene)-1,3-dioxane-4,6-dione (84257-12-5) → 5-(2-ethyl-5-methyl-2H-pyrazol-3-yl)-2,2-dimethyl-[1,3]dioxane-4,6-dione (955403-34-6)

Conditions	Yield
With triethylamine In methanol at 0 - 60℃; for 1.75h;	100%
With triethylamine In methanol at 0 - 60℃; for 1.75h;	100%

ethylhydrazine oxalic acid salt (6629-60-3) + acetoacetic acid methyl ester (105-45-3) → 2,4-dihydro-2-ethyl-5-methyl-3H-pyrazol-3-one (19364-68-2)

Conditions	Yield
With triethylamine In ethanol at 20 - 60℃;	99%

3-(dimethylamino)-1-(1-methyl-1H-indol-3-yl)prop-2-en-1-one (1443291-03-9) + ethylhydrazine oxalic acid salt (6629-60-3) → 3-(2-ethyl-2H-pyrazol-3-yl)-1-methyl-1H-indole (1443291-11-9)

Conditions	Yield
In acetonitrile for 18h; Solvent; Sealed tube; Reflux;	96%

4-amino-1-(methyldiphenylsilyl)pent-3-en-2-one + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-3-methyl-5-((methyldiphenylsilyl)methyl)pyrazole

Conditions	Yield
In ethanol at 20℃;	93%

ethylhydrazine oxalic acid salt (6629-60-3) → 6-ethyl-4-phenyl-isoxazolo[3,4-d]pyridazin-7(6H)-one (852617-79-9)

Conditions	Yield
Stage #1: 4-benzoyl-isoxazole-3-carboxylic acid ethyl ester With PPA at 50℃; Stage #2: ethylhydrazine oxalic acid salt at 90℃; for 5h;	93%

3-amino-1-(trimethylsilyl)but-2-en-1-one + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-3-methyl-5-(trimethylsilyl)pyrazole

Conditions	Yield
In ethanol at 20℃;	91%

4-amino-1-(tert-butyldiphenylsilyl)pent-3-en-2-one + ethylhydrazine oxalic acid salt (6629-60-3) → 5-(tert-butyldiphenylsilylmethyl)-1-ethyl-3-methylpyrazole

Conditions	Yield
In ethanol at 20℃;	91%

2-chloro-5-nitropyridine-3-carbonitrile (31309-08-7) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-5-nitro-1H-pyrazolo[3,4-b]pyridin-3-ylamine (1133430-77-9)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 1h;	88%

ethylhydrazine oxalic acid salt (6629-60-3) + methyl pyridine-3-carboximidate (57869-84-8) → N'-ethylnicotinimidohydrazide (1279105-95-1)

Conditions	Yield
With pyridine at 20℃; for 12h;	87%
With pyridine at 20℃; for 12h;	87%
With pyridine at 20℃; for 12h;	87%

2,3-dihydro-2H-furan (1191-99-7) + ethylhydrazine oxalic acid salt (6629-60-3) → 4-(Ethyl-hydrazono)-butan-1-ol

Conditions	Yield
In water for 3h; Ambient temperature;	86%

ethylhydrazine oxalic acid salt (6629-60-3) + 4-bromo-benzimidic acid ethyl ester hydrochloride → 4-bromo-N'-ethylbenzimidohydrazide hydrochloride (1184174-26-2)

Conditions	Yield
With pyridine at 20℃; for 16h;	85%

2,6 difluorobenzonitrile (1897-52-5) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-4-fluoro-1H-indazol-3-amine (1430098-27-3)

Conditions	Yield
With triethylamine In ethanol Reflux; regioselective reaction;	84%

4-bromo-2,6-difluorobenzaldehyde (537013-51-7) + ethylhydrazine oxalic acid salt (6629-60-3) → 6-bromo-1-ethyl-4-fluoro-1H-indazole

Conditions	Yield
In 1-methyl-pyrrolidin-2-one at 18 - 25℃; for 87h; Reflux;	84%

3,4-dihydro-2H-pyran (110-87-2) + ethylhydrazine oxalic acid salt (6629-60-3) → 5-Hydroxypentanal-ethylhydrazon (173033-12-0)

Conditions	Yield
In water for 3h; Ambient temperature;	83%

ethylhydrazine oxalic acid salt (6629-60-3) + 4-(2-chloro-phenyl)-2,4-dioxo-butyric acid ethyl ester (338982-35-7) → 5-(2-chlorophenyl)-1-ethyl-1H-pyrazole-3-carboxylic acid (1350825-09-0) + 3-(2-chlorophenyl)-1-ethyl-1H-pyrazole-5-carboxylic acid (1350825-16-9)

Conditions	Yield
Stage #1: ethylhydrazine oxalic acid salt; 4-(2-chloro-phenyl)-2,4-dioxo-butyric acid ethyl ester With triethylamine In ethanol for 3h; Reflux; Stage #2: With ethanol; sodium hydroxide at 20℃; Stage #3: With hydrogenchloride In water	A 82% B n/a

ethylhydrazine oxalic acid salt (6629-60-3) + (15E,18E)-(12S,13S,17R,21S,23S,24R)-17-Ethyl-1,16-dihydroxy-12-[(E)-2-((R)-4-hydroxy-3-methoxy-cyclohexyl)-1-methyl-vinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-aza-tricyclo[22.3.1.04,9]octacosa-15,18-diene-2,3,10,14-tetraone → C45H71N3O10

Conditions	Yield
With 4-methyl-morpholine In ethanol for 0.75h; Heating;	81%

ethylhydrazine oxalic acid salt (6629-60-3) + 2-Chloroacrylonitrile (920-37-6) → 1-ethyl-1H-pyrazole-3-amine (55361-49-4)

Conditions	Yield
With potassium carbonate In water at 45℃; for 4h;	81%
With potassium carbonate In water at 20 - 50℃;

2-fluoro-5-nitrobenzonitrile (17417-09-3) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-5-nitro-1H-indazol-3-ylamine (1133430-66-6)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80 - 90℃;	81%

ethylhydrazine oxalic acid salt (6629-60-3) + 9-isothiocyanatoacridine (7620-46-4) → 1-(9,10-dihydroacridin-9-ylidene)-2-(ethyl)thiosemicarbazide (1210368-77-6)

Conditions	Yield
With triethylamine In dichloromethane at 20℃;	80%

2-cyanocyclohexanone (4513-77-3) + ethylhydrazine oxalic acid salt (6629-60-3) → 2-ethyl-4,5,6,7-tetrahydro-2H-indazol-3-amine (1353569-74-0)

Conditions	Yield
In ethanol for 18h; Reflux; Inert atmosphere;	79%
In ethanol for 18h; Reflux;	79%
With sodium acetate In ethanol Reflux;	3.94 g

(Z)-5-Amino-1-phenyl-hex-4-en-3-one (114042-90-9) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-5-methyl-3-(2-phenylethyl)pyrazole + 1-ethyl-3-methyl-5-(2-phenylethyl)pyrazole

Conditions	Yield
With hydrogenchloride In ethanol at 20℃; for 24h;	A n/a B 78%

di-tert-butyl dicarbonate (24424-99-5) + ethylhydrazine oxalic acid salt (6629-60-3) + Cyclopropanecarboxaldehyde (1489-69-6) → N'-[1-cyclopropyl-meth-(E)-ylidene]-N-ethyl-hydrazinecarboxylic acid tert-butyl ester (845751-78-2)

Conditions	Yield
Stage #1: di-tert-butyl dicarbonate; ethylhydrazine oxalic acid salt With triethylamine In methanol for 1h; Stage #2: Cyclopropanecarboxaldehyde for 2h;	77%

bromocyane (506-68-3) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethylhydrazine-1-carbonitrile

Conditions	Yield
With sodium carbonate In N,N-dimethyl-formamide at 0℃; for 3h;	75%

trimethylacetylacetonitrile (59997-51-2) + ethylhydrazine oxalic acid salt (6629-60-3) → 3-(tert-butyl)-1-ethyl-1H-pyrazol-5-amine (874136-24-0)

Conditions	Yield
In ethanol for 18h; Reflux; Inert atmosphere;	74%
In ethanol at 75℃; for 18h;

tert-butyl 13-cyclohexyl-6-((2E,Z)-3-(dimethylamino)-2-(ethoxycarbonyl)-2-propenoyl)-3-methoxy-7H-indolo[2,1-a][2]benzazepine-10-carboxylate (1127234-89-2) + ethylhydrazine oxalic acid salt (6629-60-3) → 13-cyclohexyl-6-[4-(ethoxycarbonyl)-1-ethyl-1H-pyrazol-5-yl]-3-methoxy-7H-indolo[2,1-a][2]benzazepine-10-carboxylic acid 1,1-dimethylethyl ester (1127236-29-6)

Conditions	Yield
In ethyl acetate at 20 - 80℃; for 3h;	72%

4-methoxyacetoacetic acid methylester (41051-15-4) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-3-(methoxymethyl)-1H-pyrazol-5-ol

Conditions	Yield
Stage #1: ethylhydrazine oxalic acid salt With triethylamine In methanol for 0.166667h; Stage #2: 4-methoxyacetoacetic acid methylester With sodium hydroxide In methanol Reflux;	72%

methyl (2E)-3-methoxy-2-propenoate (5788-17-0) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-1H-pyrazol-5-ol (107296-34-4)

Conditions	Yield
Stage #1: ethylhydrazine oxalic acid salt With sodium hydroxide In water at 40℃; pH=9.5; Stage #2: methyl (2E)-3-methoxy-2-propenoate With sodium hydroxide In water at 40℃; for 4h; pH=9.0 - 9.5;	71%

4-Aminopent-3-en-2-one (1118-66-7) + ethylhydrazine oxalic acid salt (6629-60-3) → 1-ethyl-3,5-dimethylpyrazole (17629-26-4)

Conditions	Yield
With acetic acid In ethanol at 20℃; for 24h;	70%

ethyl 2-amino-2-(phenylhydrazono)acetate (1105634-63-6, 36999-43-6) + ethylhydrazine oxalic acid salt (6629-60-3) → N-ethylbenzo[d][1,3]dioxole-5-carbohydrazide (1409962-78-2)

Conditions	Yield
Stage #1: ethyl 2-amino-2-(phenylhydrazono)acetate With 2,3,4,5,6-pentafluorophenol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 20℃; for 3.08h; Stage #2: ethylhydrazine oxalic acid salt With N-ethyl-N,N-diisopropylamine In dichloromethane at 20℃; for 0.0833333h;	70%

3-bromo-4-[2-(4-cyano-2-fluoro-phenyl)-2-oxo-ethyl]-benzoic acid tert-butyl ester (866625-14-1) + ethylhydrazine oxalic acid salt (6629-60-3) → 3-Bromo-4-(6-cyano-1-ethyl-1H-indazol-3-ylmethyl)-benzoic acid tert-butyl ester (866625-15-2)

Conditions	Yield
With pyridine In ethanol at 150℃; for 0.5h; Microwave irradiation;	68%

Downstream Products

• 17629-26-4 1-ethyl-3,5-dimethylpyrazole 
• 301219-18-1 4-(3-benzyl-1-ethyl-pyrazol-5-yl)piperidine 
• 301219-20-5 4-(5-benzyl-1-ethyl-1H-pyrazol-3-yl)-piperidine 
• 313512-98-0 4-(5-benzyl-1-ethyl-(1H)-pyrazol-3-yl)-1-(t-butoxycarbonyl)piperidine 
• 301219-12-5 4-(3-Benzyl-1-ethyl-(1H-pyrazol-5-yl))-1-(tert-butoxy-carbonyl)piperidine 
• 758675-01-3 4-[2-ethyl-5-(4-methoxy-benzyl)-2H-pyrazol-3-yl]-piperidine 
• 301220-05-3 4-[2-ethyl-5-(4-fluoro-benzyl)-2H-pyrazol-3-yl]-piperidine 
• 781603-85-8 4-[2-ethyl-5-(3-fluoro-benzyl)-2H-pyrazol-3-yl]-piperidine 
• 702635-15-2 4-[5-(4-chloro-benzyl)-2-ethyl-2H-pyrazol-3-yl]-piperidine