6-Fluoro-3-hydroxypyrazine-2-carboxamide supplier

Name
Pyrazinecarboxamide, 6-fluoro-3,4-dihydro-3-oxo- (9CI)
EINECS 1533716-785-6
CAS No. 259793-96-9
Article Data24
CAS DataBase
Density 1.78 g/cm³
Solubility
Melting Point
Formula C₅H₄FN₃O₂
Boiling Point 552.6 °C at 760 mmHg
Molecular Weight 157.104
Flash Point 288 °C
Transport Information
Appearance
Safety
Risk Codes
Molecular Structure
Hazard Symbols
Synonyms Pyrazinecarboxamide,6-fluoro-3,4-dihydro-3-oxo- (9CI);6-Fluoro-3-hydroxy-2-pyrazinecarboxamide;Favipiravir;T 705 (pharmaceutical);
PSA 88.84000
LogP -0.29180

Synthetic route

: 356783-31-8
6-fluoro-3-hydroxy-2-cyanopyrazine

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Stage #1: 6-fluoro-3-hydroxy-2-cyanopyrazine With sulfuric acid at 50℃; for 4h; Stage #2: With water at 3 - 10℃; for 0.666667h; Stage #3: With sodium hydroxide In water at 10℃; for 0.75h;	92.3%
With sodium hydroxide In water at 5 - 45℃; for 5.5h; Large scale;	91%
With sulfuric acid at 50℃; for 4h;	68.43%
Stage #1: 6-fluoro-3-hydroxy-2-cyanopyrazine With dihydrogen peroxide; sodium hydroxide at 10 - 20℃; for 1h; Stage #2: With N-ethyl-N,N-diisopropylamine In ethyl acetate at 80℃; for 1h; Reagent/catalyst;

: C6H5FN2O3

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With ammonium carbonate Reagent/catalyst;	92.3%

: 356783-29-4
3,6-difluoro-2-pyrazinecarboxamide

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With water; sodium hydroxide at 60℃; for 3h;	92.1%
With sodium hydrogencarbonate In 1,4-dioxane; water at 60℃; for 8h;	82%
With water; sodium hydrogencarbonate at 50℃; for 8.5h;	65%

: 356783-28-3
3,6-difluoropyrazine-2-carbonitrile

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Stage #1: 3,6-difluoropyrazine-2-carbonitrile With sodium acetate In tetrahydrofuran; water for 20h; Reflux; Stage #2: With dihydrogen peroxide; sodium hydroxide In water; toluene at 0 - 20℃; for 4h;	89.6%
Multi-step reaction with 2 steps 1.1: sodium acetate; water / toluene; dimethyl sulfoxide / 7 h / 50 °C 2.1: sulfuric acid / 4 h / 50 °C 2.2: 0.67 h / 3 - 10 °C 2.3: 0.75 h / 10 °C View Scheme
Multi-step reaction with 2 steps 1: hydrogenchloride / tetrahydrofuran / 1.5 h / 60 °C 2: sodium hydrogencarbonate / 1,4-dioxane; water / 8 h / 60 °C View Scheme

: 1137606-74-6
dicyclohexylamine salt

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Stage #1: dicyclohexylamine salt With water; sodium hydroxide In toluene at 20℃; for 0.5h; Stage #2: With dihydrogen peroxide In toluene at 15 - 25℃; for 0.5h;	84%
Stage #1: dicyclohexylamine salt With sodium hydroxide In water; toluene at 15 - 25℃; for 0.5h; Stage #2: With water; dihydrogen peroxide at 15 - 30℃; Stage #3: With hydrogenchloride In water

: C12H10FN3O2

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With ammonia; sodium In tetrahydrofuran at -70 - -65℃;	72%

: 55321-99-8
2-hydroxypyrazine-3-carboxamide

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With 1-fluoro-4-methyl-1,4-diazoniabicyclo<2.2.2>octane ditetrafluoroborate In 1,2-dichloro-ethane; N,N-dimethyl-formamide at 70 - 80℃; for 20h; Reagent/catalyst; Solvent; Temperature;	71.3%
With fluorine In water
Multi-step reaction with 5 steps 1.1: bromine / acetonitrile / 6 h / 0 - 40 °C 2.1: trichlorophosphate / chlorobenzene / 0.5 h / 60 °C 2.2: 2.67 h / 90 - 100 °C 3.1: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 2.5 h / 60 °C 4.1: sodium acetate; water / toluene; dimethyl sulfoxide / 7 h / 50 °C 5.1: sulfuric acid / 4 h / 50 °C 5.2: 0.67 h / 3 - 10 °C 5.3: 0.75 h / 10 °C View Scheme
Multi-step reaction with 4 steps 1.1: pyridine; N-chloro-succinimide / acetonitrile / 4 h / 80 - 85 °C / Inert atmosphere 2.1: N-ethyl-N,N-diisopropylamine; phosphorus(V) oxybromide / chlorobenzene / 4 h / 0 °C / Reflux 3.1: potassium fluoride / N,N-dimethyl-formamide / 20 h / 80 - 85 °C 4.1: sodium acetate / tetrahydrofuran; water / 20 h / Reflux 4.2: 4 h / 0 - 20 °C View Scheme
Multi-step reaction with 3 steps 1.1: potassium carbonate; tetra-(n-butyl)ammonium iodide / acetonitrile / 55 - 60 °C 2.1: formic acid / 5 - 10 °C 2.2: 5 - 8 °C 3.1: ammonia; sodium / tetrahydrofuran / -70 - -65 °C View Scheme

: 3-hydroxy-6-bromopyrazine-2-carboxamide

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With potassium fluoride; 18-crown-6 ether In toluene at 100℃; for 20h;	15.96%
Multi-step reaction with 4 steps 1.1: trichlorophosphate / chlorobenzene / 0.5 h / 60 °C 1.2: 2.67 h / 90 - 100 °C 2.1: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 2.5 h / 60 °C 3.1: sodium acetate; water / toluene; dimethyl sulfoxide / 7 h / 50 °C 4.1: sulfuric acid / 4 h / 50 °C 4.2: 0.67 h / 3 - 10 °C 4.3: 0.75 h / 10 °C View Scheme
Multi-step reaction with 4 steps 1: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C 2: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C 3: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice 4: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 4 steps 1.1: trichlorophosphate / 0.25 h / 70 °C 1.2: 6 h / 20 - 100 °C 1.3: 1 h 2.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C 3.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C 4.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C View Scheme
Multi-step reaction with 3 steps 1: diethylamino-sulfur trifluoride / dichloromethane / 5 h / 0 °C 2: 18-crown-6 ether; potassium fluoride / toluene / 20 h / 110 °C 3: methanol; sodium hydrogencarbonate; water / 8 h / 50 °C View Scheme

: 6-fluoro-3-methoxy-2-pyrazinecarboxamide

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With chloro-trimethyl-silane; sodium chloride; sodium thiosulfate In chloroform; water; acetonitrile
With chloro-trimethyl-silane; sodium iodide; sodium chloride; sodium thiosulfate In chloroform; water; acetonitrile

: 356783-27-2
methyl 6-fluoro-3-oxo-3,4-dihydro-2-pyrazinecarboxylate

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With sodium bicarbonate; sodium chloride; ammonia In methanol; water; ethyl acetate

: 356783-31-8
6-fluoro-3-oxo-3,4-dihydro-2-pyrazinecarbonitrile

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With sodium hydroxide; sulfuric acid; dihydrogen peroxide In water

: 356783-42-1
3-amino-6-fluoro-2-pyrazinecarboxamide

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
With sodium bicarbonate; sodium chloride; sulfuric acid; sodium nitrite In (2S)-N-methyl-1-phenylpropan-2-amine hydrate; di-isopropyl ether; water; ethyl acetate

: 356783-16-9
3,6-dichloropyrazine-2-carbonitrile

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 3 steps 1.1: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 2.5 h / 60 °C 2.1: sodium acetate; water / toluene; dimethyl sulfoxide / 7 h / 50 °C 3.1: sulfuric acid / 4 h / 50 °C 3.2: 0.67 h / 3 - 10 °C 3.3: 0.75 h / 10 °C View Scheme
Multi-step reaction with 3 steps 1: potassium fluoride; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 55 °C / Sealed tube 2: dihydrogen peroxide / 2 h / 27 °C 3: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 3 steps 1: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C 2: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice 3: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme

: 1374986-08-9
C9H8ClN3O3

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 3 steps 1.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 2.1: sodium hydrogencarbonate; water / 4 h / 100 °C 2.2: 1.17 h / 20 °C 3.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 3.2: 0.5 h / 15 - 25 °C View Scheme

: 1374986-19-2
C9H8FN3O3

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1.1: sodium hydrogencarbonate; water / 4 h / 100 °C 1.2: 1.17 h / 20 °C 2.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 2.2: 0.5 h / 15 - 25 °C View Scheme

: 1374986-28-3
C9H10N4O6S

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1.1: potassium fluoride / dimethyl sulfoxide / 3 h / 80 °C / Inert atmosphere 1.2: 3 h / 80 °C 1.3: 20 °C 2.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 2.2: 0.5 h / 15 - 25 °C View Scheme

: 1374986-36-3
C9H12N2O4

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 5 steps 1.1: acetyl chloride; isopentyl nitrite / isopropyl alcohol / 1.5 h / 5 - 40 °C / Inert atmosphere 2.1: trichlorophosphate / toluene; N,N-dimethyl-formamide / 7 h / 15 - 70 °C / Inert atmosphere 3.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 4.1: sodium hydrogencarbonate; water / 4 h / 100 °C 4.2: 1.17 h / 20 °C 5.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 5.2: 0.5 h / 15 - 25 °C View Scheme

Yield

Multi-step reaction with 5 steps
1.1: acetyl chloride; isopentyl nitrite / isopropyl alcohol / 1.5 h / 5 - 40 °C / Inert atmosphere
2.1: trichlorophosphate / toluene; N,N-dimethyl-formamide / 7 h / 15 - 70 °C / Inert atmosphere
3.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C
4.1: sodium hydrogencarbonate; water / 4 h / 100 °C
4.2: 1.17 h / 20 °C
5.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C
5.2: 0.5 h / 15 - 25 °C
View Scheme

: 1374986-38-5
C9H11N3O5

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 4 steps 1.1: trichlorophosphate / toluene; N,N-dimethyl-formamide / 7 h / 15 - 70 °C / Inert atmosphere 2.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 3.1: sodium hydrogencarbonate; water / 4 h / 100 °C 3.2: 1.17 h / 20 °C 4.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 4.2: 0.5 h / 15 - 25 °C View Scheme

: C11H15N2O6(1-)*K(1+)

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 7 steps 1.1: trifluoroacetic acid; hydroxylamine hydrochloride / methanol / 5 h / 10 °C / Inert atmosphere; Reflux 2.1: toluene-4-sulfonic acid; acetic acid / 2 h / 77 - 80 °C / Industrial scale 3.1: trichlorophosphate; triethylamine hydrochloride / 4 h / 85 °C 4.1: triethylamine / 2 h / 80 °C 5.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 6.1: sodium hydrogencarbonate; water / 4 h / 100 °C 6.2: 1.17 h / 20 °C 7.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 7.2: 0.5 h / 15 - 25 °C View Scheme

Yield

Multi-step reaction with 7 steps
1.1: trifluoroacetic acid; hydroxylamine hydrochloride / methanol / 5 h / 10 °C / Inert atmosphere; Reflux
2.1: toluene-4-sulfonic acid; acetic acid / 2 h / 77 - 80 °C / Industrial scale
3.1: trichlorophosphate; triethylamine hydrochloride / 4 h / 85 °C
4.1: triethylamine / 2 h / 80 °C
5.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C
6.1: sodium hydrogencarbonate; water / 4 h / 100 °C
6.2: 1.17 h / 20 °C
7.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C
7.2: 0.5 h / 15 - 25 °C
View Scheme

: 1374986-03-4
C11H17N3O6

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 6 steps 1.1: toluene-4-sulfonic acid; acetic acid / 2 h / 77 - 80 °C / Industrial scale 2.1: trichlorophosphate; triethylamine hydrochloride / 4 h / 85 °C 3.1: triethylamine / 2 h / 80 °C 4.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 5.1: sodium hydrogencarbonate; water / 4 h / 100 °C 5.2: 1.17 h / 20 °C 6.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 6.2: 0.5 h / 15 - 25 °C View Scheme

Yield

Multi-step reaction with 6 steps
1.1: toluene-4-sulfonic acid; acetic acid / 2 h / 77 - 80 °C / Industrial scale
2.1: trichlorophosphate; triethylamine hydrochloride / 4 h / 85 °C
3.1: triethylamine / 2 h / 80 °C
4.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C
5.1: sodium hydrogencarbonate; water / 4 h / 100 °C
5.2: 1.17 h / 20 °C
6.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C
6.2: 0.5 h / 15 - 25 °C
View Scheme

: 1374986-04-5
C7H5N3O4

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 5 steps 1.1: trichlorophosphate; triethylamine hydrochloride / 4 h / 85 °C 2.1: triethylamine / 2 h / 80 °C 3.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 4.1: sodium hydrogencarbonate; water / 4 h / 100 °C 4.2: 1.17 h / 20 °C 5.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 5.2: 0.5 h / 15 - 25 °C View Scheme

: 1374986-05-6
methyl-5-chloroisoxazolo[4,5-b]pyrazine-3-carboxylate

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 4 steps 1.1: triethylamine / 2 h / 80 °C 2.1: potassium fluoride / dimethyl sulfoxide / 4 h / 90 °C 3.1: sodium hydrogencarbonate; water / 4 h / 100 °C 3.2: 1.17 h / 20 °C 4.1: water; sodium hydroxide / toluene / 0.5 h / 20 °C 4.2: 0.5 h / 15 - 25 °C View Scheme

: 19847-12-2
2-pyrazine carbonitrile

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 5 steps 1.1: acetic acid; dihydrogen peroxide / 22 h / -5 - 95 °C 2.1: trichlorophosphate / 1.83 h / 50 - 70 °C 2.2: 6 h / 96 °C 3.1: potassium fluoride; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 55 °C / Sealed tube 4.1: dihydrogen peroxide / 2 h / 27 °C 5.1: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme

: 18960-19-5
1,4-dioxopyrazinamide

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 4 steps 1.1: trichlorophosphate / 1.83 h / 50 - 70 °C 1.2: 6 h / 96 °C 2.1: potassium fluoride; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 55 °C / Sealed tube 3.1: dihydrogen peroxide / 2 h / 27 °C 4.1: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 4 steps 1.1: trichlorophosphate / chlorobenzene / 1.83 h / 50 - 70 °C 1.2: 8 h / 110 °C 2.1: tetrabutyl ammonium fluoride; tetrabutylammomium bromide / 3 h / 60 °C / Sealed tube 3.1: sodium acetate; water / 1,4-dioxane / 7 h / 55 °C 4.1: sulfuric acid / 4 h / 50 °C View Scheme

: 5424-01-1
3-aminopyrazinoic acid

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 8 steps 1: sulfuric acid / 20 °C / Cooling with ice 2: N-Bromosuccinimide / acetonitrile / 20 °C 3: sulfuric acid; sodium nitrite / 2 h / -5 - 20 °C 4: ammonium hydroxide / 3 h / 20 °C 5: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C 6: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C 7: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice 8: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 8 steps 1.1: sulfuric acid / 48 h / Cooling with ice 2.1: N-Bromosuccinimide / acetonitrile / 24 h / 20 °C / Inert atmosphere 3.1: sulfuric acid; sodium nitrite / 2 h / -5 - 25 °C 3.2: 1.5 h 4.1: ammonium hydroxide / 3 h / 20 °C 5.1: trichlorophosphate / 0.25 h / 70 °C 5.2: 6 h / 20 - 100 °C 5.3: 1 h 6.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C 7.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C 8.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C View Scheme

Yield

Multi-step reaction with 8 steps
1: sulfuric acid / 20 °C / Cooling with ice
2: N-Bromosuccinimide / acetonitrile / 20 °C
3: sulfuric acid; sodium nitrite / 2 h / -5 - 20 °C
4: ammonium hydroxide / 3 h / 20 °C
5: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C
6: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C
7: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice
8: sodium hydrogencarbonate; water / 8.5 h / 50 °C
View Scheme

Multi-step reaction with 8 steps
1.1: sulfuric acid / 48 h / Cooling with ice
2.1: N-Bromosuccinimide / acetonitrile / 24 h / 20 °C / Inert atmosphere
3.1: sulfuric acid; sodium nitrite / 2 h / -5 - 25 °C
3.2: 1.5 h
4.1: ammonium hydroxide / 3 h / 20 °C
5.1: trichlorophosphate / 0.25 h / 70 °C
5.2: 6 h / 20 - 100 °C
5.3: 1 h
6.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C
7.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C
8.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C
View Scheme

: 16298-03-6
Methyl 3-amino-2-pyrazinecarboxylate

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 7 steps 1: N-Bromosuccinimide / acetonitrile / 20 °C 2: sulfuric acid; sodium nitrite / 2 h / -5 - 20 °C 3: ammonium hydroxide / 3 h / 20 °C 4: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C 5: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C 6: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice 7: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 7 steps 1.1: N-Bromosuccinimide / acetonitrile / 24 h / 20 °C / Inert atmosphere 2.1: sulfuric acid; sodium nitrite / 2 h / -5 - 25 °C 2.2: 1.5 h 3.1: ammonium hydroxide / 3 h / 20 °C 4.1: trichlorophosphate / 0.25 h / 70 °C 4.2: 6 h / 20 - 100 °C 4.3: 1 h 5.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C 6.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C 7.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C View Scheme

Yield

Multi-step reaction with 7 steps
1: N-Bromosuccinimide / acetonitrile / 20 °C
2: sulfuric acid; sodium nitrite / 2 h / -5 - 20 °C
3: ammonium hydroxide / 3 h / 20 °C
4: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C
5: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C
6: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice
7: sodium hydrogencarbonate; water / 8.5 h / 50 °C
View Scheme

Multi-step reaction with 7 steps
1.1: N-Bromosuccinimide / acetonitrile / 24 h / 20 °C / Inert atmosphere
2.1: sulfuric acid; sodium nitrite / 2 h / -5 - 25 °C
2.2: 1.5 h
3.1: ammonium hydroxide / 3 h / 20 °C
4.1: trichlorophosphate / 0.25 h / 70 °C
4.2: 6 h / 20 - 100 °C
4.3: 1 h
5.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C
6.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C
7.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C
View Scheme

: 6966-01-4
methyl 3-amino-6-bromopyrazine-2-carboxylate

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 6 steps 1: sulfuric acid; sodium nitrite / 2 h / -5 - 20 °C 2: ammonium hydroxide / 3 h / 20 °C 3: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C 4: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C 5: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice 6: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 6 steps 1.1: sulfuric acid; sodium nitrite / 2 h / -5 - 25 °C 1.2: 1.5 h 2.1: ammonium hydroxide / 3 h / 20 °C 3.1: trichlorophosphate / 0.25 h / 70 °C 3.2: 6 h / 20 - 100 °C 3.3: 1 h 4.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C 5.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C 6.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C View Scheme
Multi-step reaction with 5 steps 1: sulfuric acid; sodium nitrite / 0.5 h / 0 - 60 °C 2: bromine; potassium carbonate / tetrahydrofuran / 12 h / 66 °C 3: tetrabutylammomium bromide; potassium fluoride / dimethyl sulfoxide; toluene / 3 h / 80 °C 4: hydrogen; palladium 10% on activated carbon / methanol / 4 h / 20 - 25 °C 5: ammonium carbonate View Scheme

: 21874-61-3
3-hydroxy-6-bromopyrazine-2-carboxylic acid methyl ester

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 5 steps 1: ammonium hydroxide / 3 h / 20 °C 2: trichlorophosphate; N-ethyl-N,N-diisopropylamine / water / 8 h / 60 - 100 °C 3: potassium fluoride; tetrabutylammomium bromide / toluene; dimethyl sulfoxide / 3 h / 55 °C 4: dihydrogen peroxide / toluene; dimethyl sulfoxide / 2 h / 27 °C / Cooling with ice 5: sodium hydrogencarbonate; water / 8.5 h / 50 °C View Scheme
Multi-step reaction with 5 steps 1.1: ammonium hydroxide / 3 h / 20 °C 2.1: trichlorophosphate / 0.25 h / 70 °C 2.2: 6 h / 20 - 100 °C 2.3: 1 h 3.1: potassium fluoride dihydrate; tetrabutylammomium bromide / dimethyl sulfoxide / 3 h / 50 °C 4.1: potassium carbonate; dihydrogen peroxide / dimethyl sulfoxide; water / 1.5 h / 25 °C 5.1: sodium hydrogencarbonate; water / dimethyl sulfoxide / 8 h / 50 °C View Scheme
Multi-step reaction with 4 steps 1: bromine; potassium carbonate / tetrahydrofuran / 12 h / 66 °C 2: tetrabutylammomium bromide; potassium fluoride / dimethyl sulfoxide; toluene / 3 h / 80 °C 3: hydrogen; palladium 10% on activated carbon / methanol / 4 h / 20 - 25 °C 4: ammonium carbonate View Scheme

: 486424-37-7
3-amino-6-bromo-pyrazine-2-carboxylic acid

: 259793-96-9
favipiravir

Conditions

Conditions	Yield
Multi-step reaction with 6 steps 1: sulfuric acid / 48 h / 0 - 40 °C 2: sulfuric acid; sodium nitrite / 0.5 h / 0 - 60 °C 3: bromine; potassium carbonate / tetrahydrofuran / 12 h / 66 °C 4: tetrabutylammomium bromide; potassium fluoride / dimethyl sulfoxide; toluene / 3 h / 80 °C 5: hydrogen; palladium 10% on activated carbon / methanol / 4 h / 20 - 25 °C 6: ammonium carbonate View Scheme

: tetraethyl {[(2-hydroxypropane-1,3-diyl)bis(oxy)]bis(ethylene)}bis(phosphonate)

: 259793-96-9
favipiravir

: tetraethyl 5-((3-carbamoyl-5-fluoropyrazin-2-yl)oxy)-3,7-dioxanonane-1,9-diphosphonate

Conditions

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In toluene at 60 - 65℃; for 0.166667h; Mitsunobu Displacement; Inert atmosphere;	90%

: 1383381-61-0
diethyl 2-((2-cyanoethyl)(2-hydroxyethyl)amino)ethylphosphonate

: 259793-96-9
favipiravir

A: diethyl 3-(2-(3-carbamoyl-5-fluoro-2-oxopyrazin-1-yl)ethyl)-5-cyano-3-azapentanephosphonate

B: diethyl 3-(2-((3-carbamoyl-5-fluoropyrazin-2-yl)oxy)ethyl)-5-cyano-3-azapentanephosphonate

Conditions

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In toluene at 60 - 65℃; for 0.166667h; Mitsunobu Displacement; Inert atmosphere; Overall yield = 93 %;	A 23% B 70%

...Expand

: 1332338-67-6
tetraethyl 2,2'-(2-hydroxyethylazanediyl)bis(ethane-2,1-diyl)diphosphonate

: 259793-96-9
favipiravir

A: tetraethyl 3-(2-(3-carbamoyl-5-fluoro-2-oxopyrazin-1-yl)ethyl)-3-azapentane-1,5-diphosphonate

B: tetraethyl 3-(2-((3-carbamoyl-5-fluoropyrazin-2-yl)oxy)ethyl)-3-azapentane-1,5-diphosphonate

Conditions

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In toluene at 60 - 65℃; for 0.166667h; Solvent; Temperature; Time; Mitsunobu Displacement; Inert atmosphere; Overall yield = 94 %;	A 39% B 55%

...Expand

: diethyl [2-(2-hydroxyethoxy)ethyl]phosphonate

: 259793-96-9
favipiravir

: diethyl 5-((3-carbamoyl-5-fluoropyrazin-2-yl)oxy)-3-oxapentanephosphonate

Conditions

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In toluene at 60 - 65℃; for 0.166667h; Mitsunobu Displacement; Inert atmosphere;	51%

: 1383381-63-2
diethyl 2-((2-hydroxyethyl)(2-(trityloxy)ethyl)amino)ethylphosphonate

: 259793-96-9
favipiravir

A: diethyl 3-(2-((3-carbamoyl-5-fluoropyrazin-2-yl)oxy)ethyl)-5-trityloxy-3-azapentanephosphonate

B: diethyl 3-(2-(3-carbamoyl-5-fluoro-2-oxopyrazin-1-yl)ethyl)-5-trityloxy-3-azapentanephosphonate

Conditions

Conditions	Yield
With di-isopropyl azodicarboxylate; triphenylphosphine In toluene at 60 - 65℃; for 0.166667h; Mitsunobu Displacement; Inert atmosphere; Overall yield = 73 %;	A 49% B 24%

...Expand

: 990-91-0
dibenzyl [[bis(benzyloxy)phosphoryl]oxy]phosphonate

: 259793-96-9
favipiravir

: dibenzyl (3-carbamoyl-5-fluoropyrazin-2-yl) phosphate

Conditions

Conditions	Yield
Stage #1: favipiravir With sodium hydride In N,N-dimethyl-formamide for 1h; Inert atmosphere; Stage #2: dibenzyl [[bis(benzyloxy)phosphoryl]oxy]phosphonate In N,N-dimethyl-formamide at 20℃; for 3h; Inert atmosphere;	36%

: 139757-72-5
[2-[[tert-butyl(diphenyl)silyl]oxymethyl]-1,3-oxathiolan-5-yl] acetate

: 259793-96-9
favipiravir

: trans-4-(2'-(tert-butyl-diphenylsilyloxy)methyl-1',3'-oxathiolan-5'-yl)-6-fluoro-3,4-dihydro-3-oxo-2-pyrazine-carboxamide

: cis-4-(2'-(tert-butyl-diphenylsilyloxy)methyl-1',3'-oxathiolan-5'-yl)-6-fluoro-3,4-dihydro-3-oxo-2-pyrazine-carboxamide

Conditions

Conditions	Yield
Stage #1: favipiravir With N,O-bis-(trimethylsilyl)-acetamide In acetonitrile at 20℃; for 1.5h; Inert atmosphere; Cooling with ice; Stage #2: [2-[[tert-butyl(diphenyl)silyl]oxymethyl]-1,3-oxathiolan-5-yl] acetate With tin(IV) chloride In acetonitrile at 20℃; for 0.333333h; Inert atmosphere; Cooling with ice;	A 30.8% B 11.8%

...Expand

: 2-tert-butyldiphenylsilyloxymethyl-4-acetyl-1,3-oxathiolane

: 259793-96-9
favipiravir

: cis-4-(2'-(t-butyl-diphenylsilyloxy)methyl-1',3'-oxathiolan-4'-yl)-6-fluoro-3,4-dihydro-3-oxo-2-pyrazine-carboxamide

: trans-4-(2'-(t-butyl-diphenylsilyloxy)methyl-1',3'-oxathiolan-4'-yl)-6-fluoro-3,4-dihydro-3-oxo-2-pyrazinecarboxamide

Conditions

Conditions	Yield
Stage #1: favipiravir With N,O-bis-(trimethylsilyl)-acetamide In acetonitrile at 20℃; for 1.5h; Inert atmosphere; Cooling with ice; Stage #2: 2-tert-butyldiphenylsilyloxymethyl-4-acetyl-1,3-oxathiolane With tin(IV) chloride In acetonitrile at 20℃; for 0.333333h; Inert atmosphere; Cooling with ice;	A 12.7% B 27%

...Expand

: 929911-63-7
((3-((methylsulfonyl)oxy)cyclobutyl)methyl)benzoate

: 259793-96-9
favipiravir

: C17H16FN3O4

Conditions

Conditions	Yield
Stage #1: favipiravir With sodium hydride In N,N-dimethyl-formamide; mineral oil at 20℃; for 1h; Stage #2: ((3-((methylsulfonyl)oxy)cyclobutyl)methyl)benzoate In N,N-dimethyl-formamide; mineral oil at 130℃; for 25h;	26%

: 10416-59-8
N,O-bis-(trimethylsilyl)-acetamide

: 259793-96-9
favipiravir

: 6-fluoro-3-((trimethylsilyl)oxy)pyrazine-2-carboxamide

Conditions

Conditions	Yield
In acetonitrile at 0 - 20℃; for 1.5h;

: 259793-96-9
favipiravir

: 1366418-99-6
6-fluoro-3-hydroxy-2-pyrazinecarboxamide monosodium salt

Conditions

Conditions	Yield
With sodium hydroxide In water pH=7; Reagent/catalyst; Solvent; pH-value; Temperature;

: 6284-40-8
1-deoxy-1-(methylamino)-D-glucitol

: 259793-96-9
favipiravir

: 1370365-08-4
6-fluoro-3-hydroxy-2-pyrazinecarboxamide meglumine salt

Conditions

Conditions	Yield
In water Concentration; Temperature;

6-Fluoro-3-hydroxypyrazine-2-carboxamide Specification

The 6-Fluoro-3-hydroxypyrazine-2-carboxamide, with the CAS registry number 259793-96-9, is also known as 2-Pyrazinecarboxamide, 6-fluoro-3-hydroxy-. It belongs to the product categories of Amide; Halide. This chemical's molecular formula is C₅H₄FN₃O₂ and formula weight is 157.10. What's more, both its IUPAC name and systematic name are the same which is called 5-Fluoro-2-oxo-1H-pyrazine-3-carboxamide.

Physical properties about this chemical are: (1)ACD/LogP: -1.74; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 0.57; (4)ACD/BCF (pH 5.5): 1.41; (5)ACD/BCF (pH 7.4): 1; (6)ACD/KOC (pH 5.5): 38.74; (7)ACD/KOC (pH 7.4): 1.29; (8)#H bond acceptors: 5; (9)#H bond donors: 3; (10)#Freely Rotating Bonds: 1; (11)Polar Surface Area: 52.98 Å²; (12)Index of Refraction: 1.662; (13)Molar Refractivity: 32.63 cm³; (14)Molar Volume: 88 cm³; (15)Surface Tension: 65.6 dyne/cm; (16)Density: 1.78 g/cm³; (17)Flash Point: 288 °C; (18)Enthalpy of Vaporization: 86.43 kJ/mol; (19)Boiling Point: 552.6 °C at 760 mmHg; (20)Vapour Pressure: 8.06E-13 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)Canonical SMILES: C1=C(N=C(C(=O)N1)C(=O)N)F
(2)InChI: InChI=1S/C5H4FN3O2/c6-2-1-8-5(11)3(9-2)4(7)10/h1H,(H2,7,10)(H,8,11)
(3)InChIKey: ZCGNOVWYSGBHAU-UHFFFAOYSA-N

Product Name

Pyrazinecarboxamide, 6-fluoro-3,4-dihydro-3-oxo- (9CI)

Synthetic route

6-Fluoro-3-hydroxypyrazine-2-carboxamide Specification

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